12x+6=21x-21

Solution for 12x+6=21x-21 equation:

Simplifying
12x + 6 = 21x + -21

Reorder the terms:
6 + 12x = 21x + -21

Reorder the terms:
6 + 12x = -21 + 21x

Solving
6 + 12x = -21 + 21x

Solving for variable 'x'.

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

Add '-21x' to each side of the equation.
6 + 12x + -21x = -21 + 21x + -21x

Combine like terms: 12x + -21x = -9x
6 + -9x = -21 + 21x + -21x

Combine like terms: 21x + -21x = 0
6 + -9x = -21 + 0
6 + -9x = -21

Add '-6' to each side of the equation.
6 + -6 + -9x = -21 + -6

Combine like terms: 6 + -6 = 0
0 + -9x = -21 + -6
-9x = -21 + -6

Combine like terms: -21 + -6 = -27
-9x = -27

Divide each side by '-9'.
x = 3

Simplifying
x = 3