12=-(6-6a)-3(a-6)

Solution for 12=-(6-6a)-3(a-6) equation:

Simplifying
12 = -1(6 + -6a) + -3(a + -6)
12 = (6 * -1 + -6a * -1) + -3(a + -6)
12 = (-6 + 6a) + -3(a + -6)

Reorder the terms:
12 = -6 + 6a + -3(-6 + a)
12 = -6 + 6a + (-6 * -3 + a * -3)
12 = -6 + 6a + (18 + -3a)

Reorder the terms:
12 = -6 + 18 + 6a + -3a

Combine like terms: -6 + 18 = 12
12 = 12 + 6a + -3a

Combine like terms: 6a + -3a = 3a
12 = 12 + 3a

Add '-12' to each side of the equation.
12 + -12 = 12 + -12 + 3a

Combine like terms: 12 + -12 = 0
0 = 12 + -12 + 3a

Combine like terms: 12 + -12 = 0
0 = 0 + 3a
0 = 3a

Solving
0 = 3a

Solving for variable 'a'.

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

Add '-3a' to each side of the equation.
0 + -3a = 3a + -3a
Remove the zero:
-3a = 3a + -3a

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

Divide each side by '-3'.
a = 0

Simplifying
a = 0