B to the second means b * b.
The short hand for b*b is b^2 on this editor or

c to the fourth means c * c * c *c
the short hand for c*c*c*c is c^4 on this editor or

The answer you want is b^2/c^4 in the answer box.
If this is wrong and you have choices, please list them and I will edit or put the answer in a comment.
Work shown above! x = 117 degrees
Answer:
16.4
Step-by-step explanation:
If it is asking for the tenth it will be the 1st one after the point and you round it to the next one.
Answer: 8π mm (in terms of π)
Step-by-step explanation:
1) The formulas for solving the circumference of a circle is πd (π times diameter).
2) 8 times π equals 8π mm.
Hopes this helps!