Well you would start with the original 4m+3.8+m=7 and since the m and 4m m are on the same side, you would add m+4m making the problem 5m+3.8=7, but the variable(m) and the regualr numbers have to be on seperate sides so you would subtract 3.8 from both sides of the equation(both sides of the = sign) so the problem would be 5m=3.2 (The 3.2 came from subtracting 3.8 from 7) but since the variable would always have to be just the letter with no number in front of it, you would divide 5m by 5 and 3.2 by 5 making the problem m=0.64 hope this helped :)