Answer:
Sarah bought 2 coach tickets and 3 first class tickets.
Step-by-step explanation:
Let c and f represent the numbers of coach and first class tickets purchased. Then c + f = 5, so that c = 5 - f.
The pricing equation is therefore
$380c + $1080f = $4000. Subbing 5 - f for c, we get the revised equation
380(5 - f) + 1080f = 4000.
After simplification, this becomes:
-380f + 1080f = 2100, or
700f = 2100.
Then f = 3 and c = 5 - f = 5 - 3 = 2.
Sarah bought 2 coach tickets and 3 first class tickets.