Please help i have no idea what this is!!

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?

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?

How to write four times a number,minus 6,is equal to theee times the number+8 as an equqtion