If the zero of (p(x)=7x+b) is (-2), what is the value of (b)?
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Answer and explanation
Correct answer: \(14\)
A zero of \(-2\) means that \(p(-2)=0\). Therefore, \(7(-2)+b=0\), so \(-14+b=0\). Hence, \(b=14\). If \(b=-14\), then \(p(-2)=-28\), not zero. Exam tip: For a linear polynomial \(ax+b\), substitute the given zero for \(x\) and set the polynomial equal to 0.
Frequently asked questions
What is the correct answer to this question?
\(14\)
Why is this the correct answer?
A zero of \(-2\) means that \(p(-2)=0\). Therefore, \(7(-2)+b=0\), so \(-14+b=0\). Hence, \(b=14\). If \(b=-14\), then \(p(-2)=-28\), not zero. Exam tip: For a linear polynomial \(ax+b\), substitute the given zero for \(x\) and set the polynomial equal to 0.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Linear polynomials.
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