Which line cuts the (y)-axis at ( (0,14) ) and decreases (y) by (30) when (x) increases by (5)?
Answer and explanation
Correct answer: \(y=-6x+14\)
When (x) increases by 5, (y) decreases by 30, so the slope is \(m=\frac{-30}{5}=-6\). Since the line passes through (0,14), its (y)-intercept is 14. Hence the equation is \(y=-6x+14\). In \(y=-30x+14\), the intercept is correct but the slope is -30, not -6. Exam tip: find the rate of change using \(\frac{\Delta y}{\Delta x}\).
Frequently asked questions
What is the correct answer to this question?
\(y=-6x+14\)
Why is this the correct answer?
When (x) increases by 5, (y) decreases by 30, so the slope is \(m=\frac{-30}{5}=-6\). Since the line passes through (0,14), its (y)-intercept is 14. Hence the equation is \(y=-6x+14\). In \(y=-30x+14\), the intercept is correct but the slope is -30, not -6. Exam tip: find the rate of change using \(\frac{\Delta y}{\Delta x}\).
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Introduction to Polynomials. Topic: Slope and y-intercept.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
