(2x+3)+(x+3)=42

Solution for (2x+3)+(x+3)=42 equation:

Simplifying
(2x + 3) + (x + 3) = 42

Reorder the terms:
(3 + 2x) + (x + 3) = 42

Remove parenthesis around (3 + 2x)
3 + 2x + (x + 3) = 42

Reorder the terms:
3 + 2x + (3 + x) = 42

Remove parenthesis around (3 + x)
3 + 2x + 3 + x = 42

Reorder the terms:
3 + 3 + 2x + x = 42

Combine like terms: 3 + 3 = 6
6 + 2x + x = 42

Combine like terms: 2x + x = 3x
6 + 3x = 42

Solving
6 + 3x = 42

Solving for variable 'x'.

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

Add '-6' to each side of the equation.
6 + -6 + 3x = 42 + -6

Combine like terms: 6 + -6 = 0
0 + 3x = 42 + -6
3x = 42 + -6

Combine like terms: 42 + -6 = 36
3x = 36

Divide each side by '3'.
x = 12

Simplifying
x = 12