Can someone help me i am so stuck on this homework

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?

Find the value of the variable and the length of each secant segment.

Write an equation for the function that includes the points (2,100)and (3,100)