When an equation solution is all real numbers then is it the same thing as having infinite solutions?

Which equations represents circles that have a diameter of 12 units and a center that lies on the y-axis? check all that apply

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?

You earn a 12% commission for every car you sell. how much is your commission if you sell a $23,000 car?