(c-12)+c+(c-12+18)=102

Solution for (c-12)+c+(c-12+18)=102 equation:

Simplifying
(c + -12) + c + (c + -12 + 18) = 102

Reorder the terms:
(-12 + c) + c + (c + -12 + 18) = 102

Remove parenthesis around (-12 + c)
-12 + c + c + (c + -12 + 18) = 102

Reorder the terms:
-12 + c + c + (-12 + 18 + c) = 102

Combine like terms: -12 + 18 = 6
-12 + c + c + (6 + c) = 102

Remove parenthesis around (6 + c)
-12 + c + c + 6 + c = 102

Reorder the terms:
-12 + 6 + c + c + c = 102

Combine like terms: -12 + 6 = -6
-6 + c + c + c = 102

Combine like terms: c + c = 2c
-6 + 2c + c = 102

Combine like terms: 2c + c = 3c
-6 + 3c = 102

Solving
-6 + 3c = 102

Solving for variable 'c'.

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

Add '6' to each side of the equation.
-6 + 6 + 3c = 102 + 6

Combine like terms: -6 + 6 = 0
0 + 3c = 102 + 6
3c = 102 + 6

Combine like terms: 102 + 6 = 108
3c = 108

Divide each side by '3'.
c = 36

Simplifying
c = 36