Question

Advance tickets for a school play went on sale. The price of each student ticket was $4 and everyone else paid $5. On the first day, no more than $80 in tickets were sold. Describe and explain the possible values of s, the number of student tickets sold, and e, the number of tickets sold to nonstudents.

Answer 1

20 were sold because 80/4=20

Answer 2

1) Step 1
Esblish the equation and restrictions
4s + 5e ≤ 80
s ≥ 0
e ≥ 0
2) Stept 2
Establish the limits for the values os s and e.
If you draw the line 4s + 5e ≤ 80. it will be easier to visualize the following explanation.
The line 4s + 5e = 80 and the two axis bound the values of s and e. 
Find the vertices
-  minimum s = 0, => maximum e = [80 - 4s] / 5 = [80 - 0] / 5 = 16
- minimum e = 0 => maximum s = [80 - 5e] / 4 = 80 / 4 = 20  
Solution: 
- s, the number of student tickets sold, may be any integer value between 0 and 16, including the limits- e, the number of tickets sold to nonstudents, may be any integer value between 0 and 20, including the l