Simplify the expression
(4 + 1) (x + 2x)

15x is the answer

4*x + 4*2x + 1*x + 1*2x =
4x + 8x + x + 2x = 15x

X^2 - 4x +(4/2^2) + y^2 + 8y + (8/2^2) = -4 + (4/2^2) + (8/2^2)(x + 2)^2 + (y + 4)^2 = -4 + 4 + 16your center is (-2, -4) and the radius is the sqrt of -4 + 4 + 16 which is 4