21=-7w+2(w+3)

Solution for 21=-7w+2(w+3) equation:

Simplifying
21 = -7w + 2(w + 3)

Reorder the terms:
21 = -7w + 2(3 + w)
21 = -7w + (3 * 2 + w * 2)
21 = -7w + (6 + 2w)

Reorder the terms:
21 = 6 + -7w + 2w

Combine like terms: -7w + 2w = -5w
21 = 6 + -5w

Solving
21 = 6 + -5w

Solving for variable 'w'.

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

Add '5w' to each side of the equation.
21 + 5w = 6 + -5w + 5w

Combine like terms: -5w + 5w = 0
21 + 5w = 6 + 0
21 + 5w = 6

Add '-21' to each side of the equation.
21 + -21 + 5w = 6 + -21

Combine like terms: 21 + -21 = 0
0 + 5w = 6 + -21
5w = 6 + -21

Combine like terms: 6 + -21 = -15
5w = -15

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

Simplifying
w = -3