Question 786954
s = how many student tickets
a = how many adult tickets


Account for tickets:  s+a=400
Account for revenue: 2s+3a=1050 


Two equations in two unknowns.
a=400-s.
2s+3(400-s)=1050
2s+1200-3s=1050
-s=1050-1200
s=1200-1050
s=150, so what is a?