I don't entirely know what you mean by 'rate of change', but I'll assume that you mean slope.
0, -4 and 3, 2 are on the coordinate plane.
From 0, we go over three to reach 3.
From -4, we go up six to reach 2.
Since slope is in essence, rise/run, we have the following fraction:
6/3, which can be re-written as 2/1 or just 2.
Hope this helps!
