Marcus wants to buy 5 baseballs. he has $35. what is the most each baseball can cost?

Can someone me with my hwplz(only the circled ones)

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?

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?