Answer
4
Work Step by Step
The aim is, step by step, to isolate $m$ on one side of the equation.
...Multiply out the parentheses, starting with the innermost,
working our way outwards:
$ 2[3m-6+2m-4]=6m-4\qquad$ ... simplify
$ 2(5m-10)=6m-4\qquad$ ... multiply
$10m-20=6m-4$
...Subtracting $6m$ from both sides removes it from the $RHS$
...Adding $20$ to both sides removes it from the $LHS$
$10m-20=6m-4\qquad .../+20-6m$
$ 10m-6m=-4+20\qquad$ ... simplify
$4m=16$
...Dividing both sides with $4$ isolates $m$ on the LHS.
$m=\displaystyle \frac{16}{4}=4$
solution: 4
