I picked the blue one, was I correct?

Find the solution of this system of equation -7x+y=-20 9x-3y=36

The ratio of the measures of the three angles in a triangle is 2: 9: 4. find the measures of the angels

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?