(x-6)+(x-6)+90=180

Solution for (x-6)+(x-6)+90=180 equation:

Simplifying
(x + -6) + (x + -6) + 90 = 180

Reorder the terms:
(-6 + x) + (x + -6) + 90 = 180

Remove parenthesis around (-6 + x)
-6 + x + (x + -6) + 90 = 180

Reorder the terms:
-6 + x + (-6 + x) + 90 = 180

Remove parenthesis around (-6 + x)
-6 + x + -6 + x + 90 = 180

Reorder the terms:
-6 + -6 + 90 + x + x = 180

Combine like terms: -6 + -6 = -12
-12 + 90 + x + x = 180

Combine like terms: -12 + 90 = 78
78 + x + x = 180

Combine like terms: x + x = 2x
78 + 2x = 180

Solving
78 + 2x = 180

Solving for variable 'x'.

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

Add '-78' to each side of the equation.
78 + -78 + 2x = 180 + -78

Combine like terms: 78 + -78 = 0
0 + 2x = 180 + -78
2x = 180 + -78

Combine like terms: 180 + -78 = 102
2x = 102

Divide each side by '2'.
x = 51

Simplifying
x = 51