a+3=2a+6-12

Solution for a+3=2a+6-12 equation:

Simplifying
a + 3 = 2a + 6 + -12

Reorder the terms:
3 + a = 2a + 6 + -12

Reorder the terms:
3 + a = 6 + -12 + 2a

Combine like terms: 6 + -12 = -6
3 + a = -6 + 2a

Solving
3 + a = -6 + 2a

Solving for variable 'a'.

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

Add '-2a' to each side of the equation.
3 + a + -2a = -6 + 2a + -2a

Combine like terms: a + -2a = -1a
3 + -1a = -6 + 2a + -2a

Combine like terms: 2a + -2a = 0
3 + -1a = -6 + 0
3 + -1a = -6

Add '-3' to each side of the equation.
3 + -3 + -1a = -6 + -3

Combine like terms: 3 + -3 = 0
0 + -1a = -6 + -3
-1a = -6 + -3

Combine like terms: -6 + -3 = -9
-1a = -9

Divide each side by '-1'.
a = 9

Simplifying
a = 9