For which value of \(k\) will the expression \((k^2-9)x^2+(k-3)x+1\) be a linear expression in \(x\)?
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Answer and explanation
Correct answer: -3
For \(k=-3\), the coefficient of \(x^2\) becomes \(k^2-9=0\), while the coefficient of \(x\) is \(-6\). Hence the expression is linear. Exam tip: for a linear expression, the \(x^2\) coefficient must be zero but the \(x\) coefficient must be non-zero.
Frequently asked questions
What is the correct answer to this question?
-3
Why is this the correct answer?
For \(k=-3\), the coefficient of \(x^2\) becomes \(k^2-9=0\), while the coefficient of \(x\) is \(-6\). Hence the expression is linear. Exam tip: for a linear expression, the \(x^2\) coefficient must be zero but the \(x\) coefficient must be non-zero.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Exploring Algebraic Identities. Topic: Quadratic expressions.
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