x+(x+3)+(2(x+3))=81

Solution for x+(x+3)+(2(x+3))=81 equation:

Simplifying
x + (x + 3) + (2(x + 3)) = 81

Reorder the terms:
x + (3 + x) + (2(x + 3)) = 81

Remove parenthesis around (3 + x)
x + 3 + x + (2(x + 3)) = 81

Reorder the terms:
x + 3 + x + (2(3 + x)) = 81
x + 3 + x + ((3 * 2 + x * 2)) = 81
x + 3 + x + ((6 + 2x)) = 81
x + 3 + x + (6 + 2x) = 81

Remove parenthesis around (6 + 2x)
x + 3 + x + 6 + 2x = 81

Reorder the terms:
3 + 6 + x + x + 2x = 81

Combine like terms: 3 + 6 = 9
9 + x + x + 2x = 81

Combine like terms: x + x = 2x
9 + 2x + 2x = 81

Combine like terms: 2x + 2x = 4x
9 + 4x = 81

Solving
9 + 4x = 81

Solving for variable 'x'.

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

Add '-9' to each side of the equation.
9 + -9 + 4x = 81 + -9

Combine like terms: 9 + -9 = 0
0 + 4x = 81 + -9
4x = 81 + -9

Combine like terms: 81 + -9 = 72
4x = 72

Divide each side by '4'.
x = 18

Simplifying
x = 18