5m + 3(2m - 5) = 18
First multiply out the brackets:
5m + 3x(2m) + 3x(-5) = 18
5m + 6m - 15 = 18
11m - 15 = 18
Now add 15 to both sides of the equation:
11m - 15 + 15 = 18 + 15
11m = 33
Now we can divide both sides of the equation by 11 to find what m equals:
(11m)/11 = 33/11
m = 3