9-15=a-3

Solution for 9-15=a-3 equation:

Simplifying
9 + -15 = a + -3

Combine like terms: 9 + -15 = -6
-6 = a + -3

Reorder the terms:
-6 = -3 + a

Solving
-6 = -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.
-6 + -1a = -3 + a + -1a

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

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

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

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

Divide each side by '-1'.
a = -3

Simplifying
a = -3