16ax + 4x 2 +16a^ 2 factor compleatly?
16ax + 4x 2 +16a^ 2 = {rearrange}
4x^2 + 16ax + 16a^2 =
4(x^2 + 4ax + 4a^2) =
4(x + 2a) (x + 2a) =
4(x + 2a)^2