5 divided by x squared is a fraction.
written mathematically would look like this
5/x^2
In order for this fraction to be true, x CANNOT equal zero. If it does, the fraction is then simply equal to 0.
In any other case, x can be both negative and positive because a negative value squared will always be positive.
For example
if x=1
5/(1)^2=5/1=5
simple.
If x=2 though, then the result is much different
5/(2)^2=5/4