In Class 10 real numbers the square root of a negative number is not real. Note that \(\sqrt{7}\) is real irrational.
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{-4}\). In Class 10 real numbers the square root of a negative number is not real. Note that \(\sqrt{7}\) is real irrational.
Step 3
Exam Tip
कक्षा 10 के वास्तविक संख्याओं में ऋणात्मक संख्या की वर्गमूल वास्तविक नहीं मानी जाती। ध्यान दें \(\sqrt{7}\) वास्तविक अपरिमेय है।
C. \(\frac{1}{2},\frac{1}{3},\sqrt{\frac{1}{4}}\) जैसे अनेक बिंदु/Many points like \(\frac{1}{2},\frac{1}{3},\sqrt{\frac{1}{4}}\)
Step 1
Concept
Between (0) and (1), there are infinitely many rational and irrational numbers. Between any two real numbers, more numbers can be found.
Step 2
Why this answer is correct
The correct answer is C. \(\frac{1}{2},\frac{1}{3},\sqrt{\frac{1}{4}}\) जैसे अनेक बिंदु / Many points like \(\frac{1}{2},\frac{1}{3},\sqrt{\frac{1}{4}}\). Between (0) and (1), there are infinitely many rational and irrational numbers. Between any two real numbers, more numbers can be found.
Step 3
Exam Tip
(0) और (1) के बीच परिमेय और अपरिमेय दोनों प्रकार की अनंत संख्याएं होती हैं। किसी भी दो वास्तविक संख्याओं के बीच और संख्याएं मिलती हैं।
A. कथन और कारण दोनों सही हैं/Both assertion and reason are correct
Step 1
Concept
Here (D=32-4(1)(7)=-19). Since (D<0), the assertion is correct.
Step 2
Why this answer is correct
The correct answer is A. कथन और कारण दोनों सही हैं / Both assertion and reason are correct. Here (D=32-4(1)(7)=-19). Since (D<0), the assertion is correct.
Step 3
Exam Tip
यहाँ (D=32-4(1)(7)=-19) है। (D<0) होने से कथन सही है।
The principal square root is always non-negative, so \(\sqrt{a^2}=|a|\). In exams do not forget the possibility of negative (a).
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{a^2}=|a|\). The principal square root is always non-negative, so \(\sqrt{a^2}=|a|\). In exams do not forget the possibility of negative (a).
Step 3
Exam Tip
मुख्य वर्गमूल हमेशा अऋणात्मक होता है, इसलिए \(\sqrt{a^2}=|a|\) है। परीक्षा में (a) ऋणात्मक होने की संभावना न भूलें।
\(\sqrt{-9}\) is not a real number, while the others are real. In exams do not take the square root of a negative number in the real number system.
Step 2
Why this answer is correct
The correct answer is A. \(\sqrt{-9}\). \(\sqrt{-9}\) is not a real number, while the others are real. In exams do not take the square root of a negative number in the real number system.
Step 3
Exam Tip
\(\sqrt{-9}\) वास्तविक संख्या नहीं है, जबकि बाकी सभी वास्तविक हैं। परीक्षा में ऋणात्मक संख्या का वर्गमूल वास्तविक संख्या पद्धति में नहीं लेते।
\(\sqrt{45}=3\sqrt{5}\), which is real and irrational. In exams do not treat the square root of a negative number as real.
Step 2
Why this answer is correct
The correct answer is C. \(\sqrt{45}\). \(\sqrt{45}=3\sqrt{5}\), which is real and irrational. In exams do not treat the square root of a negative number as real.
Step 3
Exam Tip
\(\sqrt{45}=3\sqrt{5}\), जो वास्तविक और अपरिमेय है। परीक्षा में ऋणात्मक वर्गमूल को वास्तविक संख्या न मानें।
C. कोई वास्तविक मूल नहीं है/There are no real roots
Step 1
Concept
The discriminant is (4-20=-16), which is negative, so there are no real roots. In exams do not treat a negative discriminant as real zeroes.
Step 2
Why this answer is correct
The correct answer is C. कोई वास्तविक मूल नहीं है / There are no real roots. The discriminant is (4-20=-16), which is negative, so there are no real roots. In exams do not treat a negative discriminant as real zeroes.
Step 3
Exam Tip
विविक्तकर (4-20=-16) ऋणात्मक है, इसलिए वास्तविक मूल नहीं हैं। परीक्षा में ऋणात्मक विविक्तकर को वास्तविक शून्यक नहीं मानें।
If (x) were rational then \(\sqrt{2}+x\) would be irrational. So (x) must be irrational; remember the sum rule for rational and irrational numbers.
Step 2
Why this answer is correct
The correct answer is B. (x) अपरिमेय है / (x) is irrational. If (x) were rational then \(\sqrt{2}+x\) would be irrational. So (x) must be irrational; remember the sum rule for rational and irrational numbers.
Step 3
Exam Tip
यदि (x) परिमेय होता तो \(\sqrt{2}+x\) अपरिमेय होता। इसलिए (x) अपरिमेय होना चाहिए; परीक्षा में परिमेय और अपरिमेय के योग का नियम याद रखें।
A. \(b^2-4c\) धनात्मक अपूर्ण वर्ग हो/\(b^2-4c\) is positive and not a perfect square
Step 1
Concept
For real zeroes, the discriminant must be positive, and for irrational zeroes it must not be a perfect square. This is the key check for quadratics with rational coefficients.
Step 2
Why this answer is correct
The correct answer is A. \(b^2-4c\) धनात्मक अपूर्ण वर्ग हो / \(b^2-4c\) is positive and not a perfect square. For real zeroes, the discriminant must be positive, and for irrational zeroes it must not be a perfect square. This is the key check for quadratics with rational coefficients.
Step 3
Exam Tip
वास्तविक शून्यकों के लिए विविक्तकर धनात्मक चाहिए और अपरिमेय शून्यकों के लिए वह पूर्ण वर्ग नहीं होना चाहिए। परिमेय गुणांकों वाले द्विघात में यही मुख्य जाँच है।
For \(x^2-8x+3\), (D=64-12=52), positive and not a perfect square. The other options give equal rational, non-real, or rational zeroes.
Step 2
Why this answer is correct
The correct answer is A. \(x^2-8x+3\). For \(x^2-8x+3\), (D=64-12=52), positive and not a perfect square. The other options give equal rational, non-real, or rational zeroes.
Step 3
Exam Tip
\(x^2-8x+3\) के लिए (D=64-12=52), जो धनात्मक अपूर्ण वर्ग है। बाकी विकल्पों में शून्यक समान परिमेय, अवास्तविक या परिमेय हैं।
B. (k) धनात्मक हो लेकिन पूर्ण वर्ग न हो/(k) is positive but not a perfect square
Step 1
Concept
The zeroes are \(x=\pm\sqrt{k}\). They are irrational real when (k>0) and (k) is not a perfect square.
Step 2
Why this answer is correct
The correct answer is B. (k) धनात्मक हो लेकिन पूर्ण वर्ग न हो / (k) is positive but not a perfect square. The zeroes are \(x=\pm\sqrt{k}\). They are irrational real when (k>0) and (k) is not a perfect square.
Step 3
Exam Tip
शून्यक \(x=\pm\sqrt{k}\) हैं। ये अपरिमेय वास्तविक तभी होंगे जब (k>0) और (k) पूर्ण वर्ग न हो।
The zeroes are \(x=\pm\sqrt{2}\), and \(\sqrt{2}\) is irrational. In exams, simplify square-root zeroes before deciding the type.
Step 2
Why this answer is correct
The correct answer is B. दोनों अपरिमेय हैं / Both are irrational. The zeroes are \(x=\pm\sqrt{2}\), and \(\sqrt{2}\) is irrational. In exams, simplify square-root zeroes before deciding the type.
Step 3
Exam Tip
शून्यक \(x=\pm\sqrt{2}\) हैं और \(\sqrt{2}\) अपरिमेय है। परीक्षा में वर्गमूल वाले शून्यकों को सरल करके जाँचें।
A real number that is not rational is called irrational. It can also be identified through its decimal form.
Step 2
Why this answer is correct
The correct answer is A. अपरिमेय संख्या / Irrational number. A real number that is not rational is called irrational. It can also be identified through its decimal form.
Step 3
Exam Tip
वास्तविक संख्या जो परिमेय नहीं होती वह अपरिमेय कहलाती है। इसे दशमलव से भी पहचाना जा सकता है।
\(\sqrt{18}\) is irrational and its negative is also real irrational. A negative sign does not change rationality.
Step 2
Why this answer is correct
The correct answer is A. \(-\sqrt{18}\). \(\sqrt{18}\) is irrational and its negative is also real irrational. A negative sign does not change rationality.
Step 3
Exam Tip
\(\sqrt{18}\) अपरिमेय है और उसका ऋण भी वास्तविक अपरिमेय है। ऋण चिह्न परिमेयता नहीं बदलता।
A. इनमें परिमेय और अपरिमेय दोनों शामिल हैं/They include both rational and irrational numbers
Step 1
Concept
Real numbers form the large set of rational and irrational numbers. They can be represented on the number line.
Step 2
Why this answer is correct
The correct answer is A. इनमें परिमेय और अपरिमेय दोनों शामिल हैं / They include both rational and irrational numbers. Real numbers form the large set of rational and irrational numbers. They can be represented on the number line.
Step 3
Exam Tip
वास्तविक संख्याएँ परिमेय और अपरिमेय संख्याओं का बड़ा समुच्चय हैं। संख्या रेखा पर इन्हें दर्शाया जा सकता है।
Since \(\sqrt[3]{64}=4\) and \(\sqrt[3]{x^{6}}=x^{2}\), the answer is \(4x^{2}\). In exams, divide the exponent by (3) for cube roots.
Step 2
Why this answer is correct
The correct answer is A. \(4x^{2}\). Since \(\sqrt[3]{64}=4\) and \(\sqrt[3]{x^{6}}=x^{2}\), the answer is \(4x^{2}\). In exams, divide the exponent by (3) for cube roots.
Step 3
Exam Tip
\(\sqrt[3]{64}=4\) और \(\sqrt[3]{x^{6}}=x^{2}\), इसलिए उत्तर \(4x^{2}\) है। परीक्षा में घनमूल में घात को (3) से भाग दें।
For (k=2), the discriminant is (16-8=8), positive but not a perfect square. Therefore the roots are real and irrational.
Step 2
Why this answer is correct
The correct answer is B. (k=2). For (k=2), the discriminant is (16-8=8), positive but not a perfect square. Therefore the roots are real and irrational.
Step 3
Exam Tip
(k=2) पर विविक्तकर (16-8=8), जो धनात्मक पर पूर्ण वर्ग नहीं है। इसलिए मूल वास्तविक और अपरिमेय होंगे।
(p(x)=\(x+\sqrt{5}\)2), so the zero is \(-\sqrt{5}\) twice. A perfect-square form gives a repeated zero.
Step 2
Why this answer is correct
The correct answer is A. \(-\sqrt{5}\) दो बार / \(-\sqrt{5}\) twice. (p(x)=\(x+\sqrt{5}\)2), so the zero is \(-\sqrt{5}\) twice. A perfect-square form gives a repeated zero.
Step 3
Exam Tip
(p(x)=\(x+\sqrt{5}\)2), इसलिए शून्यक \(-\sqrt{5}\) दो बार है। पूर्ण वर्ग रूप से दोहराया शून्यक मिलता है।
For (r=2), (D=16-8=8). It is positive and not a perfect square, so the zeroes are real and irrational.
Step 2
Why this answer is correct
The correct answer is A. कथन सही है / The statement is true. For (r=2), (D=16-8=8). It is positive and not a perfect square, so the zeroes are real and irrational.
Step 3
Exam Tip
(r=2) पर (D=16-8=8) है। यह धनात्मक और अपूर्ण वर्ग है, इसलिए शून्यक वास्तविक और अपरिमेय हैं।
B. जब (25-4c) धनात्मक हो पर पूर्ण वर्ग न हो/When (25-4c) is positive but not a perfect square
Step 1
Concept
For real distinct zeroes, (D>0) is required. For irrational zeroes, (D) must not be a perfect square.
Step 2
Why this answer is correct
The correct answer is B. जब (25-4c) धनात्मक हो पर पूर्ण वर्ग न हो / When (25-4c) is positive but not a perfect square. For real distinct zeroes, (D>0) is required. For irrational zeroes, (D) must not be a perfect square.
Step 3
Exam Tip
वास्तविक भिन्न शून्यकों के लिए (D>0) चाहिए। अपरिमेय शून्यकों के लिए (D) पूर्ण वर्ग नहीं होना चाहिए।
The repeated (2) is counted once for distinct zeroes. Tip: do not rewrite the same value for distinct zeroes.
Step 2
Why this answer is correct
The correct answer is A. (2) और (-5) / (2) and (-5). The repeated (2) is counted once for distinct zeroes. Tip: do not rewrite the same value for distinct zeroes.
Step 3
Exam Tip
दोहराया (2) अलग शून्यक में एक बार गिना जाता है। टिप: अलग शून्यक में समान मान पुनः न लिखें।
Divisibility and contradiction start from this equation. चरण 1: \(\sqrt{n}=\frac{p}{q}\) में वर्ग करने से \(\sqrt{n}\) हटता है। चरण 2: इससे \(p^2=nq^2\) जैसा समीकरण बनता है। चरण 3: इसी समीकरण से विभाज्यता और विरोधाभास शुरू होता है।
Since \(2^2=4\) and \(3^2=9\), \(\sqrt{7}\) lies between (2) and (3). In exams, compare squares first.
Step 2
Why this answer is correct
The correct answer is A. क्योंकि \(2^2<7<3^2\) / Because \(2^2<7<3^2\). Since \(2^2=4\) and \(3^2=9\), \(\sqrt{7}\) lies between (2) and (3). In exams, compare squares first.
Step 3
Exam Tip
\(2^2=4\) और \(3^2=9\), इसलिए \(\sqrt{7}\) संख्या रेखा पर (2) और (3) के बीच होगा। परीक्षा में पहले वर्गों की तुलना करें।
By Pythagoras the hypotenuse is \(\sqrt{1^2+1^2}=\sqrt{2}\). In such constructions always add the squares of perpendicular sides.
Step 2
Why this answer is correct
The correct answer is B. \(\sqrt{2}\). By Pythagoras the hypotenuse is \(\sqrt{1^2+1^2}=\sqrt{2}\). In such constructions always add the squares of perpendicular sides.
Step 3
Exam Tip
पाइथागोरस से कर्ण \(=\sqrt{1^2+1^2}=\sqrt{2}\) होगा। ऐसी रचनाओं में वर्गों का योग जरूर देखें।
(5) is positive, so it lies (5) units to the right of (0). In exams, remember right direction for positive numbers.
Step 2
Why this answer is correct
The correct answer is A. (5) इकाई दाईं ओर / (5) units to the right. (5) is positive, so it lies (5) units to the right of (0). In exams, remember right direction for positive numbers.
Step 3
Exam Tip
(5) धनात्मक है इसलिए यह (0) के दाईं ओर (5) इकाई पर होगा। परीक्षा में धनात्मक संख्या के लिए दाईं दिशा याद रखें।
\(\frac{3}{4}\) is greater than (0) and less than (1). In exams first compare the fraction value with nearby integers.
Step 2
Why this answer is correct
The correct answer is A. (0) और (1) के बीच / Between (0) and (1). \(\frac{3}{4}\) is greater than (0) and less than (1). In exams first compare the fraction value with nearby integers.
Step 3
Exam Tip
\(\frac{3}{4}\) का मान (1) से कम और (0) से अधिक होता है। परीक्षा में भिन्न की स्थिति पहले उसके मान से पहचानें।
Every point on the number line represents a real number. Between (1) and (2), both rational and irrational numbers can occur.
Step 2
Why this answer is correct
The correct answer is A. वास्तविक संख्याएँ / real numbers. Every point on the number line represents a real number. Between (1) and (2), both rational and irrational numbers can occur.
Step 3
Exam Tip
संख्या रेखा का प्रत्येक बिंदु एक वास्तविक संख्या दिखाता है। (1) और (2) के बीच परिमेय और अपरिमेय दोनों हो सकते हैं।
The middle number between (0) and (1) is \(\frac{0+1}{2}=\frac{1}{2}\). In exams, use the average for the midpoint.
Step 2
Why this answer is correct
The correct answer is A. \(\frac{1}{2}\). The middle number between (0) and (1) is \(\frac{0+1}{2}=\frac{1}{2}\). In exams, use the average for the midpoint.
Step 3
Exam Tip
(0) और (1) के बीच की मध्य संख्या \(\frac{0+1}{2}=\frac{1}{2}\) है। परीक्षा में मध्य संख्या के लिए औसत लें।
In a right triangle with legs (1) and (2), the hypotenuse is \(\sqrt{1^2+2^2}=\sqrt{5}\). Such lengths come from the Pythagoras theorem.
Step 2
Why this answer is correct
The correct answer is A. (1) और (2) / (1) and (2). In a right triangle with legs (1) and (2), the hypotenuse is \(\sqrt{1^2+2^2}=\sqrt{5}\). Such lengths come from the Pythagoras theorem.
Step 3
Exam Tip
समकोण त्रिभुज में भुजाएँ (1) और (2) हों तो कर्ण \(\sqrt{1^2+2^2}=\sqrt{5}\) होता है। पाइथागोरस प्रमेय से ऐसी लंबाई मिलती है।
\(\frac{7}{4}=1.75\), so it lies between (1) and (2). Think of an improper fraction in mixed or decimal form.
Step 2
Why this answer is correct
The correct answer is A. (1) और (2) / (1) and (2). \(\frac{7}{4}=1.75\), so it lies between (1) and (2). Think of an improper fraction in mixed or decimal form.
Step 3
Exam Tip
\(\frac{7}{4}=1.75\), इसलिए यह (1) और (2) के बीच है। अशुद्ध भिन्न को मिश्रित या दशमलव रूप में सोचें।
\(\frac{1}{2}=0.5\), so it lies between (0) and (1). Thinking of a fraction as a decimal helps locate it.
Step 2
Why this answer is correct
The correct answer is A. (0) और (1) / (0) and (1). \(\frac{1}{2}=0.5\), so it lies between (0) and (1). Thinking of a fraction as a decimal helps locate it.
Step 3
Exam Tip
\(\frac{1}{2}=0.5\), इसलिए यह (0) और (1) के बीच है। भिन्न को दशमलव में सोचने से स्थान स्पष्ट होता है।
A. यह कोई वास्तविक शून्यक नहीं देता/It gives no real zero
Step 1
Concept
(x-4-16=\(x^2-4\)\(x^2+4\)). The factor \(x^2+4\) is never (0) for real (x).
Step 2
Why this answer is correct
The correct answer is A. यह कोई वास्तविक शून्यक नहीं देता / It gives no real zero. (x-4-16=\(x^2-4\)\(x^2+4\)). The factor \(x^2+4\) is never (0) for real (x).
Step 3
Exam Tip
(x-4-16=\(x^2-4\)\(x^2+4\)) है। \(x^2+4\) वास्तविक (x) के लिए कभी (0) नहीं होता।
(p(x)=3\(x^2-4x+5\)=3((x-2)2+1)), which is always positive. Hence there are no real zeroes.
Step 2
Why this answer is correct
The correct answer is A. कोई वास्तविक शून्यक नहीं / No real zeroes. (p(x)=3\(x^2-4x+5\)=3((x-2)2+1)), which is always positive. Hence there are no real zeroes.
Step 3
Exam Tip
(p(x)=3\(x^2-4x+5\)=3((x-2)2+1)), जो सदा धनात्मक है। इसलिए कोई वास्तविक शून्यक नहीं है।
(x-2-2x+2=(x-1)2+1), which is positive for every real (x). Hence it has no real zeroes.
Step 2
Why this answer is correct
The correct answer is A. कोई वास्तविक शून्यक नहीं / No real zeroes. (x-2-2x+2=(x-1)2+1), which is positive for every real (x). Hence it has no real zeroes.
Step 3
Exam Tip
(x-2-2x+2=(x-1)2+1), जो हर वास्तविक (x) के लिए धनात्मक है। इसलिए इसका कोई वास्तविक शून्यक नहीं है।
(\(2^5\)^{\frac{2}{5}}=22=4) and (\(3^3\)^{\frac{1}{3}}=3), so the product is (12). In exams, apply the power of a power law.
Step 2
Why this answer is correct
The correct answer is A. (,12,). (\(2^5\)^{\frac{2}{5}}=22=4) and (\(3^3\)^{\frac{1}{3}}=3), so the product is (12). In exams, apply the power of a power law.
Step 3
Exam Tip
(\(2^5\)^{\frac{2}{5}}=22=4) और (\(3^3\)^{\frac{1}{3}}=3), इसलिए गुणनफल (12) है। परीक्षा में power of power नियम लगाएं।
\(125^{\frac{2}{3}}=25\) and \(25^{\frac{1}{2}}=5\), so the value is (5). In exams, separate fractional exponents into root and power.
Step 2
Why this answer is correct
The correct answer is A. (,5,). \(125^{\frac{2}{3}}=25\) and \(25^{\frac{1}{2}}=5\), so the value is (5). In exams, separate fractional exponents into root and power.
Step 3
Exam Tip
\(125^{\frac{2}{3}}=25\) और \(25^{\frac{1}{2}}=5\), इसलिए मान (5) है। परीक्षा में fractional exponents को root और power में अलग करें।
\(4^{-1}-5^{-1}=\dfrac{1}{4}-\dfrac{1}{5}=\dfrac{1}{20}\), so the whole value is (20). In exams, first convert negative powers into fractions.
Step 2
Why this answer is correct
The correct answer is A. (,20,). \(4^{-1}-5^{-1}=\dfrac{1}{4}-\dfrac{1}{5}=\dfrac{1}{20}\), so the whole value is (20). In exams, first convert negative powers into fractions.
Step 3
Exam Tip
\(4^{-1}-5^{-1}=\dfrac{1}{4}-\dfrac{1}{5}=\dfrac{1}{20}\), इसलिए पूरा मान (20) है। परीक्षा में negative powers को पहले fractions में बदलें।
\(\sqrt{98}=7\sqrt{2}\), \(\sqrt{72}=6\sqrt{2}\), and \(\sqrt{50}=5\sqrt{2}\), so the answer is \(8\sqrt{2}\). In exams, first write all surds in simplest form.
Step 2
Why this answer is correct
The correct answer is A. \(,8\sqrt{2},\). \(\sqrt{98}=7\sqrt{2}\), \(\sqrt{72}=6\sqrt{2}\), and \(\sqrt{50}=5\sqrt{2}\), so the answer is \(8\sqrt{2}\). In exams, first write all surds in simplest form.
Step 3
Exam Tip
\(\sqrt{98}=7\sqrt{2}\), \(\sqrt{72}=6\sqrt{2}\) और \(\sqrt{50}=5\sqrt{2}\), इसलिए उत्तर \(8\sqrt{2}\) है। परीक्षा में पहले सभी surds को simplest form में लिखें।
Inside, \(2^{-3}+2^{-2}=\dfrac{1}{8}+\dfrac{1}{4}=\dfrac{3}{8}\), so the power (-1) gives \(\dfrac{8}{3}\). In exams, simplify the bracket first.
Step 2
Why this answer is correct
The correct answer is A. \(,\dfrac{8}{3},\). Inside, \(2^{-3}+2^{-2}=\dfrac{1}{8}+\dfrac{1}{4}=\dfrac{3}{8}\), so the power (-1) gives \(\dfrac{8}{3}\). In exams, simplify the bracket first.
Step 3
Exam Tip
अंदर \(2^{-3}+2^{-2}=\dfrac{1}{8}+\dfrac{1}{4}=\dfrac{3}{8}\), इसलिए (-1) घात से \(\dfrac{8}{3}\) मिलता है। परीक्षा में bracket को पहले सरल करें।
Since \(\sqrt{8}=2\sqrt{2}\), (\(\sqrt{2}+\sqrt{8}\)2=\(3\sqrt{2}\)2=18). In exams, simplify the surd before squaring.
Step 2
Why this answer is correct
The correct answer is A. (,18,). Since \(\sqrt{8}=2\sqrt{2}\), (\(\sqrt{2}+\sqrt{8}\)2=\(3\sqrt{2}\)2=18). In exams, simplify the surd before squaring.
Step 3
Exam Tip
क्योंकि \(\sqrt{8}=2\sqrt{2}\), इसलिए (\(\sqrt{2}+\sqrt{8}\)2=\(3\sqrt{2}\)2=18)। परीक्षा में वर्ग करने से पहले surd सरल करें।
\(\dfrac{\sqrt{48}}{\sqrt{3}}=\sqrt{16}=4\) and \(\dfrac{\sqrt{75}}{\sqrt{3}}=\sqrt{25}=5\), so the sum is (9). In exams, simplify the division inside the root.
Step 2
Why this answer is correct
The correct answer is A. (,9,). \(\dfrac{\sqrt{48}}{\sqrt{3}}=\sqrt{16}=4\) and \(\dfrac{\sqrt{75}}{\sqrt{3}}=\sqrt{25}=5\), so the sum is (9). In exams, simplify the division inside the root.
Step 3
Exam Tip
\(\dfrac{\sqrt{48}}{\sqrt{3}}=\sqrt{16}=4\) और \(\dfrac{\sqrt{75}}{\sqrt{3}}=\sqrt{25}=5\), इसलिए योग (9) है। परीक्षा में root के अंदर भाग को सरल करें।
\(\sqrt{12}=2\sqrt{3}\) and \(\sqrt{27}=3\sqrt{3}\), so the inside value is \(-\sqrt{3}\) and the product is (-6). In exams, simplify the surds first.
Step 2
Why this answer is correct
The correct answer is A. (,-6,). \(\sqrt{12}=2\sqrt{3}\) and \(\sqrt{27}=3\sqrt{3}\), so the inside value is \(-\sqrt{3}\) and the product is (-6). In exams, simplify the surds first.
Step 3
Exam Tip
\(\sqrt{12}=2\sqrt{3}\) और \(\sqrt{27}=3\sqrt{3}\), इसलिए अंदर का मान \(-\sqrt{3}\) है और गुणनफल (-6) है। परीक्षा में पहले surd को सरल करें।
Because (\(5x^2\)0=1), \(x^0=1\), and \(2^{-1}=\dfrac{1}{2}\), the value is (4). In exams, apply the zero exponent rule only to a non-zero base.
Step 2
Why this answer is correct
The correct answer is A. (,4,). Because (\(5x^2\)0=1), \(x^0=1\), and \(2^{-1}=\dfrac{1}{2}\), the value is (4). In exams, apply the zero exponent rule only to a non-zero base.
Step 3
Exam Tip
क्योंकि (\(5x^2\)0=1), \(x^0=1\) और \(2^{-1}=\dfrac{1}{2}\), इसलिए मान (4) है। परीक्षा में शून्य घात का नियम केवल non-zero आधार पर लगाएं।
On expansion, ((2m-n)2=4m-2-4mn+n-2) and ((m+n)2=m-2+2mn+n-2), so the difference is \(3m^2-6mn\). In exams, check the signs carefully.
Step 2
Why this answer is correct
The correct answer is A. \(,3m^2-6mn,\). On expansion, ((2m-n)2=4m-2-4mn+n-2) and ((m+n)2=m-2+2mn+n-2), so the difference is \(3m^2-6mn\). In exams, check the signs carefully.
Step 3
Exam Tip
विस्तार करने पर ((2m-n)2=4m-2-4mn+n-2) और ((m+n)2=m-2+2mn+n-2), इसलिए अंतर \(3m^2-6mn\) है। परीक्षा में चिन्हों की जांच करें।
Multiplying by \(\sqrt{7}-\sqrt{5}\) makes the denominator (7-5=2) and gives \(\sqrt{7}-\sqrt{5}\). In exams, use the conjugate.
Step 2
Why this answer is correct
The correct answer is A. \(,\sqrt{7}-\sqrt{5},\). Multiplying by \(\sqrt{7}-\sqrt{5}\) makes the denominator (7-5=2) and gives \(\sqrt{7}-\sqrt{5}\). In exams, use the conjugate.
Step 3
Exam Tip
हर को \(\sqrt{7}-\sqrt{5}\) से गुणा करने पर हर (7-5=2) होता है और उत्तर \(\sqrt{7}-\sqrt{5}\) मिलता है। परीक्षा में conjugate का प्रयोग करें।
\(\sqrt{75}=5\sqrt{3}\), \(\sqrt{12}=2\sqrt{3}\), and \(\sqrt{48}=4\sqrt{3}\), so the answer is \(7\sqrt{3}\). In exams, combine only terms with the same radical part.
Step 2
Why this answer is correct
The correct answer is A. \(,7\sqrt{3},\). \(\sqrt{75}=5\sqrt{3}\), \(\sqrt{12}=2\sqrt{3}\), and \(\sqrt{48}=4\sqrt{3}\), so the answer is \(7\sqrt{3}\). In exams, combine only terms with the same radical part.
Step 3
Exam Tip
\(\sqrt{75}=5\sqrt{3}\), \(\sqrt{12}=2\sqrt{3}\) और \(\sqrt{48}=4\sqrt{3}\), इसलिए उत्तर \(7\sqrt{3}\) है। परीक्षा में समान मूल वाले पद ही जोड़ें।
Since \(25^{\frac{3}{2}}=125\) and \(125^{\frac{2}{3}}=25\), the value is (5). In exams, understand the root first in fractional powers.
Step 2
Why this answer is correct
The correct answer is A. (,5,). Since \(25^{\frac{3}{2}}=125\) and \(125^{\frac{2}{3}}=25\), the value is (5). In exams, understand the root first in fractional powers.
Step 3
Exam Tip
क्योंकि \(25^{\frac{3}{2}}=125\) और \(125^{\frac{2}{3}}=25\), इसलिए मान (5) है। परीक्षा में fractional powers में पहले root समझें।
\(2^{-1}+3^{-1}=\dfrac{1}{2}+\dfrac{1}{3}=\dfrac{5}{6}\), so the whole value is \(\dfrac{6}{5}\). In exams, simplify the denominator first.
Step 2
Why this answer is correct
The correct answer is A. \(,\dfrac{6}{5},\). \(2^{-1}+3^{-1}=\dfrac{1}{2}+\dfrac{1}{3}=\dfrac{5}{6}\), so the whole value is \(\dfrac{6}{5}\). In exams, simplify the denominator first.
Step 3
Exam Tip
\(2^{-1}+3^{-1}=\dfrac{1}{2}+\dfrac{1}{3}=\dfrac{5}{6}\), इसलिए पूरा मान \(\dfrac{6}{5}\) है। परीक्षा में denominator को पहले simplify करें।
Since \(\sqrt[3]{64}=4\), \(4^{-2}=\dfrac{1}{16}\). In exams, first evaluate the root and then apply the negative exponent.
Step 2
Why this answer is correct
The correct answer is A. \(,\dfrac{1}{16},\). Since \(\sqrt[3]{64}=4\), \(4^{-2}=\dfrac{1}{16}\). In exams, first evaluate the root and then apply the negative exponent.
Step 3
Exam Tip
क्योंकि \(\sqrt[3]{64}=4\), इसलिए \(4^{-2}=\dfrac{1}{16}\)। परीक्षा में पहले root का मान निकालें फिर negative exponent लगाएं।
When both expansions are added, (2mn) and (-2mn) cancel, giving \(2m^2+2n^2\). In exams, notice opposite middle terms.
Step 2
Why this answer is correct
The correct answer is A. \(,2m^2+2n^2,\). When both expansions are added, (2mn) and (-2mn) cancel, giving \(2m^2+2n^2\). In exams, notice opposite middle terms.
Step 3
Exam Tip
दोनों विस्तारों को जोड़ने पर (2mn) और (-2mn) कट जाते हैं, इसलिए \(2m^2+2n^2\) मिलता है। परीक्षा में opposite middle terms पर ध्यान दें।
Because \(a^{-2}=\dfrac{1}{a^2}=\dfrac{1}{5}\), \(\dfrac{1}{5}+5=\dfrac{26}{5}\). In exams, write \(a^{-2}\) as \(\dfrac{1}{a^2}\).
Step 2
Why this answer is correct
The correct answer is A. \(,\dfrac{26}{5},\). Because \(a^{-2}=\dfrac{1}{a^2}=\dfrac{1}{5}\), \(\dfrac{1}{5}+5=\dfrac{26}{5}\). In exams, write \(a^{-2}\) as \(\dfrac{1}{a^2}\).
Step 3
Exam Tip
क्योंकि \(a^{-2}=\dfrac{1}{a^2}=\dfrac{1}{5}\), इसलिए \(\dfrac{1}{5}+5=\dfrac{26}{5}\)। परीक्षा में \(a^{-2}\) को \(\dfrac{1}{a^2}\) लिखें।
When the two squares are added, the surd terms cancel and (7+7=14). In exams, irrational terms often cancel in conjugate expressions.
Step 2
Why this answer is correct
The correct answer is A. (,14,). When the two squares are added, the surd terms cancel and (7+7=14). In exams, irrational terms often cancel in conjugate expressions.
Step 3
Exam Tip
दोनों वर्ग जोड़ने पर surd terms कट जाते हैं और (7+7=14) मिलता है। परीक्षा में conjugate expressions में irrational terms अक्सर cancel होते हैं।
Taking \(7^4\) common in the numerator gives (\dfrac{74(7-1)}{74}=6). In exams, taking a common factor makes calculation shorter.
Step 2
Why this answer is correct
The correct answer is A. (,6,). Taking \(7^4\) common in the numerator gives (\dfrac{74(7-1)}{74}=6). In exams, taking a common factor makes calculation shorter.
Step 3
Exam Tip
ऊपर से \(7^4\) common लेने पर (\dfrac{74(7-1)}{74}=6) मिलता है। परीक्षा में समान factor common लेना गणना को छोटा करता है।
Since \(0.00032=3.2\times 10^{-4}\), \(\dfrac{3.2\times 10^{-4}}{10^{-5}}=3.2\times 10^1=32\). In exams, converting decimals to scientific notation helps.
Step 2
Why this answer is correct
The correct answer is A. (,32,). Since \(0.00032=3.2\times 10^{-4}\), \(\dfrac{3.2\times 10^{-4}}{10^{-5}}=3.2\times 10^1=32\). In exams, converting decimals to scientific notation helps.
Step 3
Exam Tip
क्योंकि \(0.00032=3.2\times 10^{-4}\), इसलिए \(\dfrac{3.2\times 10^{-4}}{10^{-5}}=3.2\times 10^1=32\)। परीक्षा में decimal को scientific notation में बदलना मदद करता है।
On expansion, ((p+q)2=p-2+2pq+q-2) and ((p-q)2=p-2-2pq+q-2), so the difference is (4pq). In exams, apply standard identities directly.
Step 2
Why this answer is correct
The correct answer is A. (,4pq,). On expansion, ((p+q)2=p-2+2pq+q-2) and ((p-q)2=p-2-2pq+q-2), so the difference is (4pq). In exams, apply standard identities directly.
Step 3
Exam Tip
विस्तार करने पर ((p+q)2=p-2+2pq+q-2) और ((p-q)2=p-2-2pq+q-2), इसलिए अंतर (4pq) है। परीक्षा में standard identities सीधे लगाएं।
Because (x-2-y-2=(x-y)(x+y)), the simplified form is (x+y). In exams, identifying difference of squares is very useful.
Step 2
Why this answer is correct
The correct answer is A. (,x+y,). Because (x-2-y-2=(x-y)(x+y)), the simplified form is (x+y). In exams, identifying difference of squares is very useful.
Step 3
Exam Tip
क्योंकि (x-2-y-2=(x-y)(x+y)), इसलिए सरल रूप (x+y) है। परीक्षा में difference of squares पहचानना बहुत उपयोगी है।
From \(9=3^2\), (a=2), and from \(8=2^3\), (b=3), so (a+b=5). In exams, remembering small powers gives faster solutions.
Step 2
Why this answer is correct
The correct answer is A. (,5,). From \(9=3^2\), (a=2), and from \(8=2^3\), (b=3), so (a+b=5). In exams, remembering small powers gives faster solutions.
Step 3
Exam Tip
\(9=3^2\) से (a=2) और \(8=2^3\) से (b=3), इसलिए (a+b=5)। परीक्षा में छोटे powers को याद रखना तेज समाधान देता है।
Here \(27^{\frac{2}{3}}=9\) and \(81^{\frac{1}{4}}=3\), so the product is (27). In exams, first take the root and then apply the power.
Step 2
Why this answer is correct
The correct answer is A. (,27,). Here \(27^{\frac{2}{3}}=9\) and \(81^{\frac{1}{4}}=3\), so the product is (27). In exams, first take the root and then apply the power.
Step 3
Exam Tip
यहां \(27^{\frac{2}{3}}=9\) और \(81^{\frac{1}{4}}=3\), इसलिए गुणनफल (27) है। परीक्षा में पहले मूल निकालें फिर घात लगाएं।
(\left\(\dfrac{2}{3}\right\)^{-2}=\left\(\dfrac{3}{2}\right\)2=\dfrac{9}{4}), so the product is (1). In exams, a fraction is inverted under a negative exponent.
Step 2
Why this answer is correct
The correct answer is A. (,1,). (\left\(\dfrac{2}{3}\right\)^{-2}=\left\(\dfrac{3}{2}\right\)2=\dfrac{9}{4}), so the product is (1). In exams, a fraction is inverted under a negative exponent.
Step 3
Exam Tip
(\left\(\dfrac{2}{3}\right\)^{-2}=\left\(\dfrac{3}{2}\right\)2=\dfrac{9}{4}), इसलिए गुणनफल (1) है। परीक्षा में ऋणात्मक घात में भिन्न उलट जाती है।
Multiplying by \(\sqrt{3}+\sqrt{2}\) makes the denominator (3-2=1). In exams, remember to multiply by the conjugate.
Step 2
Why this answer is correct
The correct answer is A. \(,\sqrt{3}+\sqrt{2},\). Multiplying by \(\sqrt{3}+\sqrt{2}\) makes the denominator (3-2=1). In exams, remember to multiply by the conjugate.
Step 3
Exam Tip
हर को \(\sqrt{3}+\sqrt{2}\) से गुणा करने पर हर (3-2=1) हो जाता है। परीक्षा में conjugate से गुणा करना न भूलें।
Because \(\sqrt{50}=5\sqrt{2}\), \(\sqrt{8}=2\sqrt{2}\), and \(\sqrt{18}=3\sqrt{2}\), the answer is \(4\sqrt{2}\). In exams, combine only like surd terms.
Step 2
Why this answer is correct
The correct answer is A. \(,4\sqrt{2},\). Because \(\sqrt{50}=5\sqrt{2}\), \(\sqrt{8}=2\sqrt{2}\), and \(\sqrt{18}=3\sqrt{2}\), the answer is \(4\sqrt{2}\). In exams, combine only like surd terms.
Step 3
Exam Tip
क्योंकि \(\sqrt{50}=5\sqrt{2}\), \(\sqrt{8}=2\sqrt{2}\) और \(\sqrt{18}=3\sqrt{2}\), इसलिए उत्तर \(4\sqrt{2}\) है। परीक्षा में समान surd terms को ही जोड़ें या घटाएं।
Here \(5^0=1\), \(3^{-1}=\dfrac{1}{3}\), and \(2^{-2}=\dfrac{1}{4}\), so the value is \(\dfrac{16}{3}\). In exams, first convert negative exponents into fractions.
Step 2
Why this answer is correct
The correct answer is A. \(,\dfrac{16}{3},\). Here \(5^0=1\), \(3^{-1}=\dfrac{1}{3}\), and \(2^{-2}=\dfrac{1}{4}\), so the value is \(\dfrac{16}{3}\). In exams, first convert negative exponents into fractions.
Step 3
Exam Tip
यहां \(5^0=1\), \(3^{-1}=\dfrac{1}{3}\) और \(2^{-2}=\dfrac{1}{4}\), इसलिए मान \(\dfrac{16}{3}\) है। परीक्षा में ऋणात्मक घात को पहले भिन्न में बदलें।
Here \(8=2^3\) and (42=\(2^2\)2=24), so \(\dfrac{2^5 \times 2^3}{2^4}=2^4=16\). In exams, converting numbers to the same base is useful.
Step 2
Why this answer is correct
The correct answer is A. (,16,). Here \(8=2^3\) and (42=\(2^2\)2=24), so \(\dfrac{2^5 \times 2^3}{2^4}=2^4=16\). In exams, converting numbers to the same base is useful.
Step 3
Exam Tip
यहां \(8=2^3\) और (42=\(2^2\)2=24), इसलिए \(\dfrac{2^5 \times 2^3}{2^4}=2^4=16\)। परीक्षा में सभी संख्याओं को समान आधार में बदलना उपयोगी होता है।
