D. 12.5
The equation to find the average rate of change is

To find the average rate of change between points (0,20) and (8,120) you need to plug it into the equation so it'll be

this simplifies to

which is 12.5
Answer:
12
Step-by-step explanation:
7 times 12 is 84. 4 times 21 is 84. The digits have a sum of 3.
On a graph then it is in the top left of the grid.
Distributive property means that you have to multiply everything directly outside the parent hes to everything inside the parentheses. For this problem multiply 7 to the 9x and to the -9 like so:
7(9x) + 7(-9)
63x + (-63)
63x - 63
Look at image below if you are still confused
Hope this helped!