-9-3(1-a)=0

Solution for -9-3(1-a)=0 equation:

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

Combine like terms: -9 + -3 = -12
-12 + 3a = 0

Solving
-12 + 3a = 0

Solving for variable 'a'.

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

Add '12' to each side of the equation.
-12 + 12 + 3a = 0 + 12

Combine like terms: -12 + 12 = 0
0 + 3a = 0 + 12
3a = 0 + 12

Combine like terms: 0 + 12 = 12
3a = 12

Divide each side by '3'.
a = 4

Simplifying
a = 4