18+7a-12+5a=

Solution for 18+7a-12+5a= equation:

Simplifying
18 + 7a + -12 + 5a = 0

Reorder the terms:
18 + -12 + 7a + 5a = 0

Combine like terms: 18 + -12 = 6
6 + 7a + 5a = 0

Combine like terms: 7a + 5a = 12a
6 + 12a = 0

Solving
6 + 12a = 0

Solving for variable 'a'.

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

Add '-6' to each side of the equation.
6 + -6 + 12a = 0 + -6

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

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

Divide each side by '12'.
a = -0.5

Simplifying
a = -0.5