Determine the value of x and y Answers include 45, 75, 50, 135, and 90

If you can give me the formula to solve as well as the answer I wont have trouble with it, thank you

Trish receives $450 on the first of each month. josh receives $450 on the last day of each month. both trish and josh will receive payments for next four years. at a discount rate of 9.5 percent, what is the difference in the present value of these two sets of payments?

*let m∠cob = 50°30’, m∠aob = 70° and m∠aoc = 20°30’. could point c be in the interior of ∠aob? why?

How does reflecting or rotating a figure change the interior angles of the figure?