42=-2m

Solution for 42=-2m equation:

Simplifying
42 = -2m

Solving
42 = -2m

Solving for variable 'm'.

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

Add '2m' to each side of the equation.
42 + 2m = -2m + 2m

Combine like terms: -2m + 2m = 0
42 + 2m = 0

Add '-42' to each side of the equation.
42 + -42 + 2m = 0 + -42

Combine like terms: 42 + -42 = 0
0 + 2m = 0 + -42
2m = 0 + -42

Combine like terms: 0 + -42 = -42
2m = -42

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

Simplifying
m = -21