10b-21=3b

Solution for 10b-21=3b equation:

Simplifying
10b + -21 = 3b

Reorder the terms:
-21 + 10b = 3b

Solving
-21 + 10b = 3b

Solving for variable 'b'.

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

Add '-3b' to each side of the equation.
-21 + 10b + -3b = 3b + -3b

Combine like terms: 10b + -3b = 7b
-21 + 7b = 3b + -3b

Combine like terms: 3b + -3b = 0
-21 + 7b = 0

Add '21' to each side of the equation.
-21 + 21 + 7b = 0 + 21

Combine like terms: -21 + 21 = 0
0 + 7b = 0 + 21
7b = 0 + 21

Combine like terms: 0 + 21 = 21
7b = 21

Divide each side by '7'.
b = 3

Simplifying
b = 3