18=6+a

Solution for 18=6+a equation:

Simplifying
18 = 6 + a

Solving
18 = 6 + 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.
18 + -1a = 6 + a + -1a

Combine like terms: a + -1a = 0
18 + -1a = 6 + 0
18 + -1a = 6

Add '-18' to each side of the equation.
18 + -18 + -1a = 6 + -18

Combine like terms: 18 + -18 = 0
0 + -1a = 6 + -18
-1a = 6 + -18

Combine like terms: 6 + -18 = -12
-1a = -12

Divide each side by '-1'.
a = 12

Simplifying
a = 12