What is the zero of (20-5x)?
Answer and explanation
Correct answer: 4
To find a zero, equate the polynomial to 0: \(20-5x=0\). Thus, \(5x=20\), so \(x=4\). Checking, \(20-5(4)=0\); hence 4 is the zero. If 5 is substituted, the value is \(-5\), not 0. Exam tip: the zero of a linear polynomial \(ax+b\) is \(-\frac{b}{a}\).
Frequently asked questions
What is the correct answer to this question?
4
Why is this the correct answer?
To find a zero, equate the polynomial to 0: \(20-5x=0\). Thus, \(5x=20\), so \(x=4\). Checking, \(20-5(4)=0\); hence 4 is the zero. If 5 is substituted, the value is \(-5\), not 0. Exam tip: the zero of a linear polynomial \(ax+b\) is \(-\frac{b}{a}\).
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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