Answer:
54
Step-by-step explanation:
Let number of adult tickets sold be [tex]a[/tex]
Let number of children tickets sold be [tex]c[/tex]
139 tickets were sold:
we can write:
[tex]a+c=139[/tex]
a total sales of $972.00:
we can write:
[tex]5.4c+9.5a=972[/tex]
Now solving for [tex]c[/tex] in the first equation and substituting that into 2nd equation, we can solve for [tex]a[/tex], what we need. So:
[tex]c=139-a\\-------\\5.4c+9.5a=972\\5.4(139-a)+9.5a=972\\750.6-5.4a+9.5a=972\\-5.4a+9.5a=972-750.6\\4.1a=221.4\\a=54[/tex]
Hence 54 adult tickets were sold.
