Write an expression for 7 less than y

Which number produces a rationale number when multiplied by 1/5

How long must $542 be invested at a rate of 7% to earn $303.52 in interest? in a easier way

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?