m∠x = 130º
1) Considering those parallel lines intercepted by a transversal one.
2) Then we can state that x:
x +50º =180º
x= 180 -50º
x=130º
This is because these angles are Consecutive Interior Angles, so they are supplementary (x +50=180º as a consequence of being part of that transversal line that intercepts those parallel ones.
3) then m∠x = 130º