Tickets for a school play sold for $7.50 for each adult and $3.00 for each child. The total receipts for 118 tickets totaled $696. Find the number of adult tickets sold.

adult tickets

Respuesta :

x= number of adult tickets
y=number of child tickets.
we can suggest this system of equations: 
x+y=118                 ⇒x=118-y
7.5x+3y=696

we can solve this system of equations by substitution method:
7.5(118-y)+3y=696
885-7.5y+3y=696
-4.5y=-189
y=-189/-4.5
y=42

x=118-y
x=118-42
x=76

Answer: the number of adult tickets sold was 76.