(6+t)+(12-3t)=0

Solution for (6+t)+(12-3t)=0 equation:

Simplifying
(6 + t) + (12 + -3t) = 0

Remove parenthesis around (6 + t)
6 + t + (12 + -3t) = 0

Remove parenthesis around (12 + -3t)
6 + t + 12 + -3t = 0

Reorder the terms:
6 + 12 + t + -3t = 0

Combine like terms: 6 + 12 = 18
18 + t + -3t = 0

Combine like terms: t + -3t = -2t
18 + -2t = 0

Solving
18 + -2t = 0

Solving for variable 't'.

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

Add '-18' to each side of the equation.
18 + -18 + -2t = 0 + -18

Combine like terms: 18 + -18 = 0
0 + -2t = 0 + -18
-2t = 0 + -18

Combine like terms: 0 + -18 = -18
-2t = -18

Divide each side by '-2'.
t = 9

Simplifying
t = 9