S + a = 300...s = 300 - a
8s + 12a = 3200
8(300 - a) + 12a = 3200
2400 - 8a + 12a = 3200
-8a + 12a = 3200 - 2400
4a = 800
a = 800/4
a = 200 <==== 200 adult tickets
s = 300 - a
s = 300 - 200
s = 100 <=== 100 student tickets
Answer:
b=12
Step-by-step explanation:
Perimeter=2*(l+b)
64=2*(20+b)
b=12