3-(4+a)=12

Solution for 3-(4+a)=12 equation:

Simplifying
3 + -1(4 + a) = 12
3 + (4 * -1 + a * -1) = 12
3 + (-4 + -1a) = 12

Combine like terms: 3 + -4 = -1
-1 + -1a = 12

Solving
-1 + -1a = 12

Solving for variable 'a'.

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

Add '1' to each side of the equation.
-1 + 1 + -1a = 12 + 1

Combine like terms: -1 + 1 = 0
0 + -1a = 12 + 1
-1a = 12 + 1

Combine like terms: 12 + 1 = 13
-1a = 13

Divide each side by '-1'.
a = -13

Simplifying
a = -13