I didn't know which equation you were asking about, so I solved for both of them. I hope this helps!
Ignore the first guy who answered this question
Answer:

Step-by-step explanation:
Applying Pythagoras theorem on right angle triangle


Diameter=2 x radius

First find angle EBC.
The are for a triangle is 180 degrees.
It is a right triangle and has a right angle.
180 - (90 + 50)
180 - 140
angle EBC IS 40
NOW FIND X
The line is 180 degrees.
180 -40 = 140
X = 140 DEGREES
Answer:
C and D I think??? Could be wrong. But definitely D is one of them.
The correct answer is NO LINEAR FACTORS (option A ).