a total of 15 people took the trip. She was able to purchase coach tickets for ​110$ and first class tickets for ​940$. She used her total budget , which was ​9120$.

Answer 1

Let C = number of coach tickets purchased.

Let F = number of first class tickets purchased.

C + F = 15

110C + 940F = 9120

I will use substitution and rewrite the first equation C = 15 - F.

110(15 - F) + 940F = 9120

1650 - 110F + 940F = 9120

830F = 7470

F = 9

C = 15 - 9 = 6

Checking: 110(6) + 940(9) = 660 + 8460 = 9120

9 first class tickets and 6 coach tickets were purchased.