Which line cuts the (y)-axis at ( (0,-8) ) and increases (y) by (18) when (x) increases by (3)?

Correct answer: \(y=6x-8\)

The slope is \(\frac{\Delta y}{\Delta x}=\frac{18}{3}=6\). The point \((0,-8)\) shows that the \(y\)-intercept is \(-8\). Therefore, using slope-intercept form \(y=mx+c\), the line is \(y=6x-8\). In \(y=18x-8\), the intercept is correct, but the slope is 18, not 6. Exam tip: find the slope from the changes first, then use the point with \(x=0\) to identify the \(y\)-intercept.