If (y=100-kx) and (y=76) at (x=4), what is (k)?
Answer and explanation
Correct answer: 6
Given \(x=4\) and \(y=76\), substitute these values in \(y=100-kx\): \(76=100-4k\). Hence, \(4k=24\), so \(k=6\). Option 24 is the value of \(4k\), not of \(k\). Exam tip: In a linear expression, substitute the given values of \(x\) and \(y\) first, then isolate the unknown term.
Frequently asked questions
What is the correct answer to this question?
6
Why is this the correct answer?
Given \(x=4\) and \(y=76\), substitute these values in \(y=100-kx\): \(76=100-4k\). Hence, \(4k=24\), so \(k=6\). Option 24 is the value of \(4k\), not of \(k\). Exam tip: In a linear expression, substitute the given values of \(x\) and \(y\) first, then isolate the unknown term.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Linear growth and decay.
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