(-3a+9)-(3a+6)=

Solution for (-3a+9)-(3a+6)= equation:

Simplifying
(-3a + 9) + -1(3a + 6) = 0

Reorder the terms:
(9 + -3a) + -1(3a + 6) = 0

Remove parenthesis around (9 + -3a)
9 + -3a + -1(3a + 6) = 0

Reorder the terms:
9 + -3a + -1(6 + 3a) = 0
9 + -3a + (6 * -1 + 3a * -1) = 0
9 + -3a + (-6 + -3a) = 0

Reorder the terms:
9 + -6 + -3a + -3a = 0

Combine like terms: 9 + -6 = 3
3 + -3a + -3a = 0

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

Solving
3 + -6a = 0

Solving for variable 'a'.

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

Add '-3' to each side of the equation.
3 + -3 + -6a = 0 + -3

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

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

Divide each side by '-6'.
a = 0.5

Simplifying
a = 0.5