Which of the following is the simplified form of \(\sqrt{192}-\sqrt{27}\)?
Answer and explanation
Correct answer: \(5\sqrt{3}\)
Simplify each radical: \(\sqrt{192}=\sqrt{64\times3}=8\sqrt{3}\) and \(\sqrt{27}=\sqrt{9\times3}=3\sqrt{3}\). So the difference is \(8\sqrt{3}-3\sqrt{3}=(8-3)\sqrt{3}=5\sqrt{3}\). The nearest distractor \(3\sqrt{3}\) equals \(\sqrt{27}\), not the difference; a common mistake is to confuse one term with the result. Exam tip: pull out perfect squares first and then combine like surd terms by adding/subtracting their coefficients.
Frequently asked questions
What is the correct answer to this question?
\(5\sqrt{3}\)
Why is this the correct answer?
Simplify each radical: \(\sqrt{192}=\sqrt{64\times3}=8\sqrt{3}\) and \(\sqrt{27}=\sqrt{9\times3}=3\sqrt{3}\). So the difference is \(8\sqrt{3}-3\sqrt{3}=(8-3)\sqrt{3}=5\sqrt{3}\). The nearest distractor \(3\sqrt{3}\) equals \(\sqrt{27}\), not the difference; a common mistake is to confuse one term with the result. Exam tip: pull out perfect squares first and then combine like surd terms by adding/subtracting their coefficients.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Polynomials. Topic: Irrational numbers and real numbers.
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