Which of the following is an element

Sets are a great way to make any question confusing.

We're interested in the intersection of all three sets. There's no need for the parentheses; intersection is associative.

An element in the intersection is an element in all three sets, so a whole number (doesn't rule out any choices), perfect square between 1 and 9 (rules out 3, 6 and 16 but 4 remains) and an even number between 2 and 9 (4 is in that one too).

Second choice: 4

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value

.there can be infinite values of m and n that can satisfy the above equation. for each value of m of m or n. there maybe infinite sets of solution for the above

step-by-step explanation: