If a quantity starts at (22) and increases by (4) each step, which rule represents it?
Answer and explanation
Correct answer: \(y=22+4x\)
The starting quantity is 22, so when \(x=0\), the value of \(y\) must be 22. Since it increases by 4 at every step, the coefficient of \(x\) is \(+4\). Therefore, the rule is \(y=22+4x\). In option C, the initial value and the rate of increase have been interchanged. Exam tip: in \(y=a+bx\), \(a\) is the initial value and \(b\) is the change per step.
Frequently asked questions
What is the correct answer to this question?
\(y=22+4x\)
Why is this the correct answer?
The starting quantity is 22, so when \(x=0\), the value of \(y\) must be 22. Since it increases by 4 at every step, the coefficient of \(x\) is \(+4\). Therefore, the rule is \(y=22+4x\). In option C, the initial value and the rate of increase have been interchanged. Exam tip: in \(y=a+bx\), \(a\) is the initial value and \(b\) is the change per step.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Linear growth and decay.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
