Im in 7th. can anyone follow me on insta?

Taking algebra two apex courses and need with these questions

Phyllis and chen are saving money to go to a football game. each friend starts with some money and saves a specific amount each week. phyllis made a graph to show the total she has saved at the end of each week. chen wrote an equation to show the total, y, he has saved at the end of each week, x. y = 15x + 15 compare the amount that each friend has when both friends start saving. select the correct answer from the drop-down menu to complete the statement. phyllis starts with $ and chen starts with $

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