42=8b+13b

Solution for 42=8b+13b equation:

Simplifying
42 = 8b + 13b

Combine like terms: 8b + 13b = 21b
42 = 21b

Solving
42 = 21b

Solving for variable 'b'.

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

Add '-21b' to each side of the equation.
42 + -21b = 21b + -21b

Combine like terms: 21b + -21b = 0
42 + -21b = 0

Add '-42' to each side of the equation.
42 + -42 + -21b = 0 + -42

Combine like terms: 42 + -42 = 0
0 + -21b = 0 + -42
-21b = 0 + -42

Combine like terms: 0 + -42 = -42
-21b = -42

Divide each side by '-21'.
b = 2

Simplifying
b = 2