Easy
ok, so
for y=a(x-h)^2+k
the vertex is (h,k)
given that the the vertex is (-2,-20)
y=a(x-(-2))^2+(-20)
y=a(x+2)^2-20
find a
when x=0, then y=-12
-12=a(0+2)^2-20
-12=a(2)^2-20
8=4a
2=a
equation is
y=2(x+2)^2-20
if the last term is positive, then maybe y=2(x+2)^2+(-20)?
unless you typed something wrong, then you are right that the last term is -20
Given:
<u>Step</u><u> </u><u>by</u><u> step</u><u> explanation</u><u>:</u>
Step 1:

Step 2:

Step 3:

Step 4:

Step 5:

Step 6:

The patterns are multiplying by three!
Answer:
Can you show the whole question
The installation fee is a one time thing so you do 375-50. and then you do 325/25 to get 13 so the answer is 13 months