(3x-6)(3x+6)=20

Solution for (3x-6)(3x+6)=20 equation:

Simplifying
(3x + -6)(3x + 6) = 20

Reorder the terms:
(-6 + 3x)(3x + 6) = 20

Reorder the terms:
(-6 + 3x)(6 + 3x) = 20

Multiply (-6 + 3x) * (6 + 3x)
(-6(6 + 3x) + 3x * (6 + 3x)) = 20
((6 * -6 + 3x * -6) + 3x * (6 + 3x)) = 20
((-36 + -18x) + 3x * (6 + 3x)) = 20
(-36 + -18x + (6 * 3x + 3x * 3x)) = 20
(-36 + -18x + (18x + 9x2)) = 20

Combine like terms: -18x + 18x = 0
(-36 + 0 + 9x2) = 20
(-36 + 9x2) = 20

Solving
-36 + 9x2 = 20

Solving for variable 'x'.

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

Add '36' to each side of the equation.
-36 + 36 + 9x2 = 20 + 36

Combine like terms: -36 + 36 = 0
0 + 9x2 = 20 + 36
9x2 = 20 + 36

Combine like terms: 20 + 36 = 56
9x2 = 56

Divide each side by '9'.
x2 = 6.222222222

Simplifying
x2 = 6.222222222

Take the square root of each side:
x = {-2.494438258, 2.494438258}