Answer:
Step-by-step explanation:
c + f = 16......c = 16 - f
340c + 910f = 9430
340(16 - f) + 910f = 9430
5440 - 340f + 910f = 9430
-340f + 910f = 9430 - 5440
570f = 3990
f = 3990/570
f = 7 <====== 7 first class tickets bought
c + f = 16
c + 7 = 16
c = 16 - 7
c = 9 <====== 9 coach tickets bought