20-(x+6)(x-6)=0

Solution for 20-(x+6)(x-6)=0 equation:

Simplifying
20 + -1(x + 6)(x + -6) = 0

Reorder the terms:
20 + -1(6 + x)(x + -6) = 0

Reorder the terms:
20 + -1(6 + x)(-6 + x) = 0

Multiply (6 + x) * (-6 + x)
20 + -1(6(-6 + x) + x(-6 + x)) = 0
20 + -1((-6 * 6 + x * 6) + x(-6 + x)) = 0
20 + -1((-36 + 6x) + x(-6 + x)) = 0
20 + -1(-36 + 6x + (-6 * x + x * x)) = 0
20 + -1(-36 + 6x + (-6x + x2)) = 0

Combine like terms: 6x + -6x = 0
20 + -1(-36 + 0 + x2) = 0
20 + -1(-36 + x2) = 0
20 + (-36 * -1 + x2 * -1) = 0
20 + (36 + -1x2) = 0

Combine like terms: 20 + 36 = 56
56 + -1x2 = 0

Solving
56 + -1x2 = 0

Solving for variable 'x'.

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

Add '-56' to each side of the equation.
56 + -56 + -1x2 = 0 + -56

Combine like terms: 56 + -56 = 0
0 + -1x2 = 0 + -56
-1x2 = 0 + -56

Combine like terms: 0 + -56 = -56
-1x2 = -56

Divide each side by '-1'.
x2 = 56

Simplifying
x2 = 56

Take the square root of each side:
x = {-7.483314774, 7.483314774}