Which of the following expressions is a perfect-square trinomial for every real value of x?
Answer and explanation
Correct answer: \(x^2+6x+9\)
In \(x^2+6x+9\), the middle term is \(2\cdot x\cdot3=6x\) and the last term is \(3^2=9\), so it equals \((x+3)^2\). \(x^2+6x+8\) fails because its constant term is not 9. Exam tip: check \(a^2+2ab+b^2\).
Frequently asked questions
What is the correct answer to this question?
\(x^2+6x+9\)
Why is this the correct answer?
In \(x^2+6x+9\), the middle term is \(2\cdot x\cdot3=6x\) and the last term is \(3^2=9\), so it equals \((x+3)^2\). \(x^2+6x+8\) fails because its constant term is not 9. Exam tip: check \(a^2+2ab+b^2\).
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Exploring Algebraic Identities. Topic: Algebraic identities.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.