0+(-21)=b

Solution for 0+(-21)=b equation:

Simplifying
0 + (-21) = b
0 + -21 = b

Combine like terms: 0 + -21 = -21
-21 = b

Solving
-21 = b

Solving for variable 'b'.

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

Add '-1b' to each side of the equation.
-21 + -1b = b + -1b

Combine like terms: b + -1b = 0
-21 + -1b = 0

Add '21' to each side of the equation.
-21 + 21 + -1b = 0 + 21

Combine like terms: -21 + 21 = 0
0 + -1b = 0 + 21
-1b = 0 + 21

Combine like terms: 0 + 21 = 21
-1b = 21

Divide each side by '-1'.
b = -21

Simplifying
b = -21