Which statement is TRUE? * I. y=x^2 is a function
II. y^2=x is a function
III. y=x^2 is not a function
IV. y^2=x is not a function

Sarah took the advertising department from her company on a round trip to meet with a potential client. including sarah a total of 11 people took the trip. she was able to purchase coach tickets for $280 and first class tickets for $1280. she used her total budget for airfare for the trip, which was $6080. how many first class tickets did she buy? how many coach tickets did she buy?