Not sure about 1 and 4, since there's also a y variable, but:
2) x=2
3) x=4
5) x=7
When we plug these values into the given equation, we get undefined values, such as something divided by 0.
if we use 2 as an example, we have (x³/x²-4)
If we replace 2, we get (2³/2²-4)
Which simplifies to 8/4-4
=8/0
