-2[a+3]-a=0

Solution for -2[a+3]-a=0 equation:

Simplifying
-2[a + 3] + -1a = 0

Reorder the terms:
-2[3 + a] + -1a = 0
[3 * -2 + a * -2] + -1a = 0
[-6 + -2a] + -1a = 0

Combine like terms: -2a + -1a = -3a
-6 + -3a = 0

Solving
-6 + -3a = 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 + -3a = 0 + 6

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

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

Divide each side by '-3'.
a = -2

Simplifying
a = -2