The zero of the linear polynomial (3x+b) is (-2). What is (b)?
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Answer and explanation
Correct answer: \(6\)
Since \(-2\) is a zero, the value of the polynomial must be zero when \(x=-2\). Thus, \(3(-2)+b=0\), so \(-6+b=0\). Therefore, \(b=6\). If \(b=-6\), the polynomial value would be \(-12\), not zero. Exam tip: When a zero is given, substitute it for \(x\) and equate the polynomial to zero.
Frequently asked questions
What is the correct answer to this question?
\(6\)
Why is this the correct answer?
Since \(-2\) is a zero, the value of the polynomial must be zero when \(x=-2\). Thus, \(3(-2)+b=0\), so \(-6+b=0\). Therefore, \(b=6\). If \(b=-6\), the polynomial value would be \(-12\), not zero. Exam tip: When a zero is given, substitute it for \(x\) and equate the polynomial to zero.
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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