3a+(3-a)=6

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

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

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

Reorder the terms:
3 + 3a + -1a = 6

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

Solving
3 + 2a = 6

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 + 2a = 6 + -3

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

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

Divide each side by '2'.
a = 1.5

Simplifying
a = 1.5