What is \(x^2+22x+121\) equal to?
Answer and explanation
Correct answer: \((x+11)^2\)
\(x^2+22x+121=x^2+2\cdot x\cdot11+11^2\). Using the perfect-square identity \(a^2+2ab+b^2=(a+b)^2\), it equals \((x+11)^2\). Option B would produce the middle term \(-22x\), so it is incorrect. Exam tip: take the square roots of the first and last terms and verify the middle term.
Frequently asked questions
What is the correct answer to this question?
\((x+11)^2\)
Why is this the correct answer?
\(x^2+22x+121=x^2+2\cdot x\cdot11+11^2\). Using the perfect-square identity \(a^2+2ab+b^2=(a+b)^2\), it equals \((x+11)^2\). Option B would produce the middle term \(-22x\), so it is incorrect. Exam tip: take the square roots of the first and last terms and verify the middle term.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Polynomials. Topic: Operations on real numbers and the laws of exponents.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
