5m + 2n + n - 3m + 7 - 3n /all you have to do is combine like terms, so all the “m”s, all the “n”s and all the integers. We can rearrange them to make it easier for us.
(5m - 3m) + (2n + n - 3n) + (7)
2m + 0 (since 3n - 3n = 0) + 7
2m + 7 is the answer. :)