80=[x+8][x-8]

Solution for 80=[x+8][x-8] equation:

Simplifying
80 = [x + 8][x + -8]

Reorder the terms:
80 = [8 + x][x + -8]

Reorder the terms:
80 = [8 + x][-8 + x]

Multiply [8 + x] * [-8 + x]
80 = [8[-8 + x] + x[-8 + x]]
80 = [[-8 * 8 + x * 8] + x[-8 + x]]
80 = [[-64 + 8x] + x[-8 + x]]
80 = [-64 + 8x + [-8 * x + x * x]]
80 = [-64 + 8x + [-8x + x2]]

Combine like terms: 8x + -8x = 0
80 = [-64 + 0 + x2]
80 = [-64 + x2]

Solving
80 = -64 + x2

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-1x2' to each side of the equation.
80 + -1x2 = -64 + x2 + -1x2

Combine like terms: x2 + -1x2 = 0
80 + -1x2 = -64 + 0
80 + -1x2 = -64

Add '-80' to each side of the equation.
80 + -80 + -1x2 = -64 + -80

Combine like terms: 80 + -80 = 0
0 + -1x2 = -64 + -80
-1x2 = -64 + -80

Combine like terms: -64 + -80 = -144
-1x2 = -144

Divide each side by '-1'.
x2 = 144

Simplifying
x2 = 144

Take the square root of each side:
x = {-12, 12}