-2(t+3)=21-5t

Solution for -2(t+3)=21-5t equation:

Simplifying
-2(t + 3) = 21 + -5t

Reorder the terms:
-2(3 + t) = 21 + -5t
(3 * -2 + t * -2) = 21 + -5t
(-6 + -2t) = 21 + -5t

Solving
-6 + -2t = 21 + -5t

Solving for variable 't'.

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

Add '5t' to each side of the equation.
-6 + -2t + 5t = 21 + -5t + 5t

Combine like terms: -2t + 5t = 3t
-6 + 3t = 21 + -5t + 5t

Combine like terms: -5t + 5t = 0
-6 + 3t = 21 + 0
-6 + 3t = 21

Add '6' to each side of the equation.
-6 + 6 + 3t = 21 + 6

Combine like terms: -6 + 6 = 0
0 + 3t = 21 + 6
3t = 21 + 6

Combine like terms: 21 + 6 = 27
3t = 27

Divide each side by '3'.
t = 9

Simplifying
t = 9