Simplifying
3[x + -1] = 12
Reorder the terms:
3[-1 + x] = 12
[-1 * 3 + x * 3] = 12
[-3 + 3x] = 12
Solving
-3 + 3x = 12
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 + 3x = 12 + 3
Combine like terms: -3 + 3 = 0
0 + 3x = 12 + 3
3x = 12 + 3
Combine like terms: 12 + 3 = 15
3x = 15
Divide each side by '3'.
x = 5
Simplifying
x = 5
