Solve the equation by factoring, by finding square roots, or by completing the square.

4(x+8)^2=144

I'm not sure if I'm suppose to divide or multiply the 4 to both sides..

you can go about it in two ways:

divide by 4 first. You want to divide by 4, because that removes it from the left side of the equation:

(x+8)^2 = 36
(x+8) = ±6
x = -8 ± 6

Or, you can think make the left side a perfect square:

[2(x+8)]^2 = 144
2(x+8) = ±12
x+8 = ±6
x = -8 ± 6