Answer:
The number of adult tickets sold was 5
Step-by-step explanation:
Let
x ----> the number of adult tickets
y ----> the number of child tickets
we know that
[tex]x+y=8[/tex]
isolate the variable y
[tex]y=8-x[/tex] ----> equation A
[tex]5.50x+3y=36.50[/tex] ----> equation B
Solve the system by substitution
substitute equation A in equation B
[tex]5.50x+3(8-x)=36.50[/tex]
solve for x
apply distributive property left side
[tex]5.50x+24-3x=36.50[/tex]
combine like terms
[tex]2.50x+24=36.50[/tex]
subtract 24 both sides
[tex]2.50x=36.50-24[/tex]
[tex]2.50x=12.50[/tex]
Divide by 2.50 both sides
[tex]x=5[/tex]
therefore
The number of adult tickets sold was 5