In order to get the answer to this question you will have to rearrange and solve the question step by step.
[tex]10=7-m[/tex]
Rearrange:
[tex]10-(7-m)=0[/tex]
[tex]10-7=3[/tex]
Rearrange once more:
[tex]m+3=0[/tex]
[tex]-3 -3[/tex]
[tex]m=-3[/tex]
Therefore the answer is "m=-3."
Hope this helps.