If (p(x)=5x-15), which value is its zero?
Answer and explanation
Correct answer: \(x=3\)
To find a zero, set \(p(x)=0\): \(5x-15=0\). Thus, \(5x=15\), so \(x=3\). On checking, \(p(3)=5(3)-15=0\); hence, \(x=3\) is the zero. Substituting \(x=5\) gives \(10\), so it is not a zero. Exam tip: verify a proposed zero by substituting it into the polynomial and checking whether the result is \(0\).
Frequently asked questions
What is the correct answer to this question?
\(x=3\)
Why is this the correct answer?
To find a zero, set \(p(x)=0\): \(5x-15=0\). Thus, \(5x=15\), so \(x=3\). On checking, \(p(3)=5(3)-15=0\); hence, \(x=3\) is the zero. Substituting \(x=5\) gives \(10\), so it is not a zero. Exam tip: verify a proposed zero by substituting it into the polynomial and checking whether the result is \(0\).
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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