Combine like terms!
You can move things around before you do so to make it easier.
-5m + 2m + 4 - 1
Now combine -5m and 2m since they have like terms.
You should end up with -3m.
Subtract 4-1 and you get 3.
Your final answer should be -3m + 3!
by the way, you have it in the wrong subject!