Answer:
This is a tough one, I see why you are confused. The answer would be 50
Explanation:
I used process of elimination and working backwards
First I took the first option (50) and added 10. Then divided it by 5 to isolate the X value. I plugged the X value into the (11x+3) and got 135. The missing angle is 45. 50+45+85=180
Hope this helped!