(Use Solving Systems by Graphing to find a solution for this question) One cellphone provider charges $10 per month plus an activation fee of $20. A second cellphone provider charges $11 per month plus an activation fee of $15. For what number of months is the cost of either cellphone provider the same?

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?