3k+6=12k-21

Solution for 3k+6=12k-21 equation:

Simplifying
3k + 6 = 12k + -21

Reorder the terms:
6 + 3k = 12k + -21

Reorder the terms:
6 + 3k = -21 + 12k

Solving
6 + 3k = -21 + 12k

Solving for variable 'k'.

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

Add '-12k' to each side of the equation.
6 + 3k + -12k = -21 + 12k + -12k

Combine like terms: 3k + -12k = -9k
6 + -9k = -21 + 12k + -12k

Combine like terms: 12k + -12k = 0
6 + -9k = -21 + 0
6 + -9k = -21

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

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

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

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

Simplifying
k = 3