First, you should distribute -8 into m + 8 to get -8m - 64. Then, you should combine -4m and -8m together to get -12m as a result. Your equation should now be -24 - 2m = -12m - 64. Add 12 on both sides to get -24 + 10m = -64. Add 24 on both sides to get -40 on the right side. Finally, divide 10 on both sides to get your m value which is -4.