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

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

Simplifying
12 + -3(a + -1) = 3 + a

Reorder the terms:
12 + -3(-1 + a) = 3 + a
12 + (-1 * -3 + a * -3) = 3 + a
12 + (3 + -3a) = 3 + a

Combine like terms: 12 + 3 = 15
15 + -3a = 3 + a

Solving
15 + -3a = 3 + a

Solving for variable 'a'.

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

Add '-1a' to each side of the equation.
15 + -3a + -1a = 3 + a + -1a

Combine like terms: -3a + -1a = -4a
15 + -4a = 3 + a + -1a

Combine like terms: a + -1a = 0
15 + -4a = 3 + 0
15 + -4a = 3

Add '-15' to each side of the equation.
15 + -15 + -4a = 3 + -15

Combine like terms: 15 + -15 = 0
0 + -4a = 3 + -15
-4a = 3 + -15

Combine like terms: 3 + -15 = -12
-4a = -12

Divide each side by '-4'.
a = 3

Simplifying
a = 3