Can someone please help me with this ASAP

Which undefined geometric term is described as a location on a coordinate plane that is designed by an ordered pair (x,y) ?

Scrub a dub toothbrushes are $4.00 each. there is a 10% discount, but there is also a 6% sales tax after the discount is applied. what is the new price after tax? round to the nearest penny

Stephen thublin invests $1,000,000 in a 45-day certificate of deposit with 6.55% interest. what is the total interest income from the investment?