Answer:
34
Step-by-step explanation:
$1.25 = 125 cents.
$42 = 4200 cents
Tickets sold at 75 cents = x
Tickets sold at 125 cents = y
x + y = 40
75x + 125y = 4200
Multiply the first equation by 75
75x + 75y = 3000
75x + 125y = 4200
Subtract the the second equation from the first.
75x + 75y = 3000
- 75x + 125y = 4200
-------------------------------
0 - 150y = - 1200
Divide both sides by - 150
-150y/-150 = -1200/-150
y = 8
Substitute y = 8 into the first equation
x + y = 42
x + 8 = 42
x = 42 - 8
x = 34
34 tickets were sold for 75 cents
8 tickets were sold for $1.25
