a = number of adults
s = number is students
8a + 5s = 3585
a + s = 525
a = 525 - s
Using substitution
8(525 - s) + 5s = 3585
4200 - 8s + 5s = 3585
-3s = 3585 - 4200 = -615
s = 105
a +(105) = 525
a = 420
Costs
$1300 + $2.50(525)
= $1300 + $1312.50
= $2612.50
profit
$3585 - $2612.50 = $972.50
Doug H.
02/18/16