2(3+3x)-3=21

Solution for 2(3+3x)-3=21 equation:

Simplifying
2(3 + 3x) + -3 = 21
(3 * 2 + 3x * 2) + -3 = 21
(6 + 6x) + -3 = 21

Reorder the terms:
6 + -3 + 6x = 21

Combine like terms: 6 + -3 = 3
3 + 6x = 21

Solving
3 + 6x = 21

Solving for variable 'x'.

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

Add '-3' to each side of the equation.
3 + -3 + 6x = 21 + -3

Combine like terms: 3 + -3 = 0
0 + 6x = 21 + -3
6x = 21 + -3

Combine like terms: 21 + -3 = 18
6x = 18

Divide each side by '6'.
x = 3

Simplifying
x = 3