If a relation is a function, how many y-values can each x-value have?
Yes.
Practice makes perfect
For a relation to be a function, each x-value can only be paired with one y-value, but one y-value can be paired with multiple x-values.
(3,- 9), (11,21), (121,34), (34,1), (23,45)
Examining the ordered pairs, we can see that there is no x-value with multiple y-values. Therefore, the relation is a function.