At a zoo, youth tickets cost $5 and adult tickets cost $9. A group that purchased x youth tickets and y adult tickets spent $90 on tickets. What is the domain of the relationship

0 ≤ x ≤ 18

Step-by-step explanation:

Let 'x' be the number of youth tickets purchased at the zoo and 'y' be the number of adult tickets purchased at the zoo.

At a zoo, youth tickets cost $5 and adult tickets cost $9. A group spent a total of $90 on tickets. We can write as

5x + 9y = 90

to find x we divide both side by 5

x = (90-9y)/5 =>  90/5 - 9y/5

x = 18 - 9y/5

The domain of the relationship is the possible set of values of x and y that satisfies the equation. The domain of this relationship is

0 ≤ x ≤ 18

At x = 0, it means only adult tickets were purchased.

At x = 18, it means only youth tickets were purchased.