Hi Rylee, this is not a Series 7 question, but please see the following explanation. The formula for slope which is designated as m=(y2-y1)/(x2-x1) which if you substitute the values above you end up with (4-9)/(-2-(-4)) which equals -5/2 or -2.5. Now using the standard form of a linear equation of y=mx+b, we know the m is -2.5 so we just need to find the b which works by plugging in either of the original points given to us. We will test both in this case. 9=-2.5*-4+b so b=-1. So we end up with y=-2.5x-1. Let's test the second point to see if it adds up. 4=-2*-2.5-1 if we simplify this 4=4 so the linear equation is proven to be correct.
