42=32-r

Solution for 42=32-r equation:

Simplifying
42 = 32 + -1r

Solving
42 = 32 + -1r

Solving for variable 'r'.

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

Add 'r' to each side of the equation.
42 + r = 32 + -1r + r

Combine like terms: -1r + r = 0
42 + r = 32 + 0
42 + r = 32

Add '-42' to each side of the equation.
42 + -42 + r = 32 + -42

Combine like terms: 42 + -42 = 0
0 + r = 32 + -42
r = 32 + -42

Combine like terms: 32 + -42 = -10
r = -10

Simplifying
r = -10