Answer:
C) 4
Step-by-step explanation:
Arcs on one side of the diameter adds upto 180°.
Therefore,

Answer:
c
Step-by-step explanation:
Answer:
C. 
Step-by-step explanation:
Consider the expression 
First, note that

Find the discriminant

Now,

Write the factored form:

Subtracting a negative integer is the same as adding a positive integer. Adding a positive integer to any number always makes the answer larger than the original number. Therefore, if you subtract one negative integer from another your answer will be always be *greater* than the integer you started with.
For number 15 and 16, you just have to find the absolute difference between the two points along the calibration of the protractor.
15. ∠BXC = |B - C| = |140° - 110°| = 30°
16. ∠BXE = |B - E| = |140° - 30°| = 110°
For numbers 20 and 21, apply the Angle Addition Postulate. This is when you add the individual interior angles to equate to the total angle.
20. ∠PQS = ∠PQR + ∠RQS
112° = 72°+ 10x°
x = 4
21. ∠KLM = ∠KLN + ∠NLM
135° = 47°+ 16y°
y = 5.5