-42=3-(-5r)

Solution for -42=3-(-5r) equation:

Simplifying
-42 = 3 + -1(-5r)

Remove parenthesis around (-5r)
-42 = 3 + -1 * -5r

Multiply -1 * -5
-42 = 3 + 5r

Solving
-42 = 3 + 5r

Solving for variable 'r'.

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

Add '-5r' to each side of the equation.
-42 + -5r = 3 + 5r + -5r

Combine like terms: 5r + -5r = 0
-42 + -5r = 3 + 0
-42 + -5r = 3

Add '42' to each side of the equation.
-42 + 42 + -5r = 3 + 42

Combine like terms: -42 + 42 = 0
0 + -5r = 3 + 42
-5r = 3 + 42

Combine like terms: 3 + 42 = 45
-5r = 45

Divide each side by '-5'.
r = -9

Simplifying
r = -9