You must combine like terms. First add 7m and -13m which makes -6m. That makes the equation -6m - 5 =25. Then add 5 on both sides, which makes -6m = 30. Finally divide -6 on both sides and the answer will be m= -5
You subtract 7m and 13m which would give you -6m after you have -6m - 5= 25 then you add 5 which gives you 30 you then you divide that by -6 which gives you m=-5