Ellie borrows money at a yearly simple interest rate of 6 1/2%. After 4 years, Ellie owes $39 in interest. How much money did Ellie borrow?

Ineed big ! the cost of a school banquet is $25 plus $15 for each person attending. create a table, sketch the graph, and write an equation in slope-intercept and point-slope form that gives total cost as a function of the number of people attending. what is the cost for 77 people?