Answer:
Step-by-step explanation:
If AB is parallel to CD and there is a transversal cutting through both (as there is, although it is not named here), then by the definition of corresponding angles, angles 1 and 5 are corresponding and are therefore, congruent. If angle 1 measures 120 then so does angle 5. Learn these...they're very important and are prevalent in triangle stuff in geometry!!!
10 = 2/3m - 3/2m
2/3m - 3/2m = 10
m ( 2/3 - 3/2 ) = 10
-5/6m = 10
5m = -60
m = -12