Answer
12
Work Step by Step
The aim is, step by step, to isolate m on one side of the equation.
Subtract 0.1m from both sides and the right side will have no x's
Add 0.5 to both sides and the left side will contain only x's.
$0.2m-0.5=0.1m+0.7\qquad .../-0.1m+0.5$
$ 0.2m-0.1m=0.7+0.5 \qquad$... simplify
$0.1m=1.2$
Multiplying both sides with 10 isolates m on the LHS
$0.1m=1.2 \qquad.../\times$10
$m=12$
Solution: 12
