3(-1+3n)-3(n+3)=12

Solution for 3(-1+3n)-3(n+3)=12 equation:

Simplifying
3(-1 + 3n) + -3(n + 3) = 12
(-1 * 3 + 3n * 3) + -3(n + 3) = 12
(-3 + 9n) + -3(n + 3) = 12

Reorder the terms:
-3 + 9n + -3(3 + n) = 12
-3 + 9n + (3 * -3 + n * -3) = 12
-3 + 9n + (-9 + -3n) = 12

Reorder the terms:
-3 + -9 + 9n + -3n = 12

Combine like terms: -3 + -9 = -12
-12 + 9n + -3n = 12

Combine like terms: 9n + -3n = 6n
-12 + 6n = 12

Solving
-12 + 6n = 12

Solving for variable 'n'.

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

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

Combine like terms: -12 + 12 = 0
0 + 6n = 12 + 12
6n = 12 + 12

Combine like terms: 12 + 12 = 24
6n = 24

Divide each side by '6'.
n = 4

Simplifying
n = 4