Explain why all sequences can be described as functions?

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

What expression is equivalent to log3(x+4)

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?