By pulling out the common factors for each pair of terms, we can rewrite the original polynomial like this:
3x(2x + 1) + 10(2x + 1)
These two terms now have a common factor of (2x + 1). Seems like we should be able to do something with that information, don't you think? In fact, we can pull out this common factor and rewrite the polynomial again:
-2m + 5 = 2m + 5
2m + 2m = 5 - 5
4m = 0
m = 0
-2m + 5 = -2m + 5
-2m + 2m = 5 - 5
0 = 0
-2m + 5 = -2m - 5
-2m + 2m = 5 + 5
0 = 10
Solution set is Ф
The third equation is the correct answer.
Convert it then you will fine the weight.