6+3*(12+x)=54

Solution for 6+3*(12+x)=54 equation:

Simplifying
6 + 3(12 + x) = 54
6 + (12 * 3 + x * 3) = 54
6 + (36 + 3x) = 54

Combine like terms: 6 + 36 = 42
42 + 3x = 54

Solving
42 + 3x = 54

Solving for variable 'x'.

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

Add '-42' to each side of the equation.
42 + -42 + 3x = 54 + -42

Combine like terms: 42 + -42 = 0
0 + 3x = 54 + -42
3x = 54 + -42

Combine like terms: 54 + -42 = 12
3x = 12

Divide each side by '3'.
x = 4

Simplifying
x = 4