Which equation represents a line that is parallel to the y-axis?

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?

Write two point-slope equations for the line passing through the points (6, 5) and (3, 1)

This is about circle theorems. someone asap : (