First you must distribute the 4 to the numbers inside the parentheses, which would be m and 2...
(4*m) + (4*2) = -4
4m + 8 = -4
Now bring 8 to the left side by subtracting 8 to both sides (what you do on one side you must do to the other). Since 8 is being added on the left side, subtraction (the opposite of addition) will cancel it out (make it zero) from the left side and bring it over to the right side.
4m + 8 - 8 = -4 - 8
4m + 0 = -12
4m = -12
Next divide 4 to both sides to finish isolating m. Since 4 is being multiplied by m, division (the opposite of multiplication) will cancel 4 out (in this case it will make 4 one) from the left side and bring it over to the right side.
4m / 4 = -12 / 4
m = -3
Hope this helped!
~Just a girl in love with Shawn Mendes