If (y=56+8x), which value of (x) makes (y) equal to (15x)?
Answer and explanation
Correct answer: \(x=8\)
Given \(y=56+8x\) and the condition \(y=15x\), we equate the two expressions: \(56+8x=15x\). Subtracting \(8x\) from both sides gives \(56=7x\), so \(x=8\). Hence, option C is correct. For instance, if \(x=7\), then \(y=112\) but \(15x=105\), so it does not satisfy the condition. Exam tip: equate the two expressions for the same variable and solve the resulting linear equation.
Frequently asked questions
What is the correct answer to this question?
\(x=8\)
Why is this the correct answer?
Given \(y=56+8x\) and the condition \(y=15x\), we equate the two expressions: \(56+8x=15x\). Subtracting \(8x\) from both sides gives \(56=7x\), so \(x=8\). Hence, option C is correct. For instance, if \(x=7\), then \(y=112\) but \(15x=105\), so it does not satisfy the condition. Exam tip: equate the two expressions for the same variable and solve the resulting linear equation.
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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