Which line cuts the (y)-axis at ((0,20)) and decreases (y) by (72) when (x) increases by (8)?

Correct answer: \(y=-9x+20\)

When \(x\) increases by \(8\), \(y\) decreases by \(72\), so the slope is \(m=\frac{-72}{8}=-9\). The line meets the \(y\)-axis at \((0,20)\), so its \(y\)-intercept is \(20\). Therefore, the equation is \(y=-9x+20\). Option \(y=-72x+20\) has the correct intercept but an incorrect slope of \(-72\). Exam tip: find the slope from the change first, then use \(y=mx+c\) with the intercept.