Answer:
Explanation:
c + f = 10 (the coach tickets + first class tickets = 10)...there is 10 people
160c + 1230f = 6950....each coach ticket is 160 and each first class ticket is 1230.....and when added, they equal 6950 (for the airfare)
c + f = 10.....c = 10 - f
160c + 1230f = 6950
sub in 10 - f for c
160(10 - f) + 1230f = 6950
distribute the 160 thru the parenthesis
1600 - 160f + 1230f = 6950
combine like terms
1600 + 1070f = 6950
subtract 1600 from both sides
1070f = 6950 - 1600
1070f = 5350
divide both sides by 1070
f = 5350/1070
f = 5 <===== she bought 5 first class tickets
c + f = 10
we found f to be 5...so sub in 5 for f and find c, the coach tickets
c + 5 = 10
c = 10 - 5
c = 5 .......and she bought 5 coach tickets
check...
160c + 1230f = 6950
160(5) + 1230(5) = 6950
800 + 6150 = 6950
6950 = 6950 (correct)....so it checks out
5 coach and 5 first class