What are the solutions to the equation x2-12x + 20 = –20?

x = 2, 10

Solve value of x by factoring, getting

(x - 2)(x - 10) = 0

Standard: x=4
implicit: x-4=0

Do you mean a cube has a surface area?
If so we identify by how many faces a cube has which is 6. That would mean to find the surface area we add each squares area to get 24. So we divide 24 and 6 to get the area of each face.

24 / 6 = 4 m^2

We know that a square has equal side lengths thus finding that A = a^2. We find the square root of 4 to get the length of each square.

sqrt 4 = 2 m