80=(x+2)(x-2)

Solution for 80=(x+2)(x-2) equation:

Simplifying
80 = (x + 2)(x + -2)

Reorder the terms:
80 = (2 + x)(x + -2)

Reorder the terms:
80 = (2 + x)(-2 + x)

Multiply (2 + x) * (-2 + x)
80 = (2(-2 + x) + x(-2 + x))
80 = ((-2 * 2 + x * 2) + x(-2 + x))
80 = ((-4 + 2x) + x(-2 + x))
80 = (-4 + 2x + (-2 * x + x * x))
80 = (-4 + 2x + (-2x + x2))

Combine like terms: 2x + -2x = 0
80 = (-4 + 0 + x2)
80 = (-4 + x2)

Solving
80 = -4 + 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 = -4 + x2 + -1x2

Combine like terms: x2 + -1x2 = 0
80 + -1x2 = -4 + 0
80 + -1x2 = -4

Add '-80' to each side of the equation.
80 + -80 + -1x2 = -4 + -80

Combine like terms: 80 + -80 = 0
0 + -1x2 = -4 + -80
-1x2 = -4 + -80

Combine like terms: -4 + -80 = -84
-1x2 = -84

Divide each side by '-1'.
x2 = 84

Simplifying
x2 = 84

Take the square root of each side:
x = {-9.16515139, 9.16515139}