Simplify;
6x + 10 + 12 - 16
This becomes
6x -6
Simplify:
-4m - 18 - 6m - 2
This becomes
-4m - 6m - 18 - 2
Notice that we have collected the "like terms" that is those parts that include the unknown which is m, and those that do not.
-10m - 20
You can leave your answer as it is or you can simplify further by saying;
Divide both numbers by -10 and you have
-10 (m +2)