2(b-21)=-5b

Solution for 2(b-21)=-5b equation:

Simplifying
2(b + -21) = -5b

Reorder the terms:
2(-21 + b) = -5b
(-21 * 2 + b * 2) = -5b
(-42 + 2b) = -5b

Solving
-42 + 2b = -5b

Solving for variable 'b'.

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

Add '5b' to each side of the equation.
-42 + 2b + 5b = -5b + 5b

Combine like terms: 2b + 5b = 7b
-42 + 7b = -5b + 5b

Combine like terms: -5b + 5b = 0
-42 + 7b = 0

Add '42' to each side of the equation.
-42 + 42 + 7b = 0 + 42

Combine like terms: -42 + 42 = 0
0 + 7b = 0 + 42
7b = 0 + 42

Combine like terms: 0 + 42 = 42
7b = 42

Divide each side by '7'.
b = 6

Simplifying
b = 6