Step-by-step explanation:
So what you can do is first get ride of the parentheses around 5-m so:
[tex]-3m - (2m + 5-m)+7[/tex]
Then, you can simplify the numbers inside the parentheses, so:
[tex]-3m-(m+5) + 7[/tex]
Then, you can get rid of the parentheses by distributing the - sign:
[tex]-3m-m-5+7[/tex]
Next, just combine like terms:
[tex]-4m + 2[/tex] or [tex]2-4m[/tex]