-21=-6+3w

Solution for -21=-6+3w equation:

Simplifying
-21 = -6 + 3w

Solving
-21 = -6 + 3w

Solving for variable 'w'.

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

Add '-3w' to each side of the equation.
-21 + -3w = -6 + 3w + -3w

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

Add '21' to each side of the equation.
-21 + 21 + -3w = -6 + 21

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

Combine like terms: -6 + 21 = 15
-3w = 15

Divide each side by '-3'.
w = -5

Simplifying
w = -5