In ( (x+6)^2=x^2+__+36 ), what will fill the blank?
Answer and explanation
Correct answer: \(12x\)
Using the identity \((a+b)^2=a^2+2ab+b^2\), put \(a=x\) and \(b=6\). Then \((x+6)^2=x^2+2\times x\times6+36=x^2+12x+36\). Therefore, the blank is \(12x\). \(36x\) is incorrect because 36 is the constant term obtained from \(6^2\). Exam tip: the middle term in the square of a binomial is always \(2ab\).
Frequently asked questions
What is the correct answer to this question?
\(12x\)
Why is this the correct answer?
Using the identity \((a+b)^2=a^2+2ab+b^2\), put \(a=x\) and \(b=6\). Then \((x+6)^2=x^2+2\times x\times6+36=x^2+12x+36\). Therefore, the blank is \(12x\). \(36x\) is incorrect because 36 is the constant term obtained from \(6^2\). Exam tip: the middle term in the square of a binomial is always \(2ab\).
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Exploring Algebraic Identities. Topic: Algebraic identities.
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