Answer:
Your equation would be
y=4x-12
Explanation:
So an easy way to figure this out is graph the points and look at the distance the points are away from each other. In this case it was 12 up and 3 right. This is your slope. Simplify the fraction to 4/1. Then from (2,-4) use the given slope to work back to a point that is on the y axis, which is (0,12). Plug all of the given information you found into y=mx+b and you get the given formula.