I don't get what there asking.

Answer:
86 adults and 270 children
Step-by-step explanation:
Let x = # of adult tickets;
then the number of children tickets is (356-x).
Write the total money equation (revenue equation)
[tex]1.75*(356-x) + 2.25x = 666[/tex] dollars.
From the equation
[tex]x = \frac{666-1.75*356}{2.25-1.75} = 86[/tex]
ANSWER. 86 adults and 356-86 = 270 children.
CHECK.
[tex]86*2.25 + 270*1.75 = 666[/tex] dollars. ! Correct !