9514 1404 393
Answer:
x = 17°
Step-by-step explanation:
The vertical angles at C are the same in each triangle, so the sums of the other two angles in the triangles are the same:
x +100° = 4x +49°
51° = 3x . . . . . . . . . . . subtract x+49°
17° = x . . . . . . . . . divide by 3