-1=3-0.4m

Solution for -1=3-0.4m equation:

Simplifying
-1 = 3 + -0.4m

Solving
-1 = 3 + -0.4m

Solving for variable 'm'.

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

Add '0.4m' to each side of the equation.
-1 + 0.4m = 3 + -0.4m + 0.4m

Combine like terms: -0.4m + 0.4m = 0.0
-1 + 0.4m = 3 + 0.0
-1 + 0.4m = 3

Add '1' to each side of the equation.
-1 + 1 + 0.4m = 3 + 1

Combine like terms: -1 + 1 = 0
0 + 0.4m = 3 + 1
0.4m = 3 + 1

Combine like terms: 3 + 1 = 4
0.4m = 4

Divide each side by '0.4'.
m = 10

Simplifying
m = 10