It can be.
If \(y < 0\) & \(x < 0\) then \(xy > 0\)

xy > 0
This means that Product of two numbers x and y is > 0

Theory: If Product of two numbers is > 0 then it means that both numbers have the same sign. Either both are positive or both are negative.

=> both x and y have the same sign
=> Either both x and y are positive or both are negative.

Let's take each option choice one by one

A. x > 0 -> This can be true as both x and y can be positive
B. y < 0 -> This can be true as both x and y can be negative
C. x + y > 0 -> This can be true as both x and y can be positive, making x + y > 0
D. x/y > 0 -> This is true as this also means that both x and y have the same sign. xy > 0 and x/y > 0 mean the same thing
E. x/y < 0 -> NOT True, as this will mean that both x and y have different signs

So, answer will be E
Hope it helps!

To learn more about inequality watch the below video

If xy > 0, which of the following CANNOT be true?
if xy > 0, then x and y must have the same sign

Correct Answer: E
x/y < 0 => Both positive and both negative integers will result in values > 0