Question 697745
In general, for value of a function to be defined for real numbers two things must be true:<br>

1) All values under a square root (or even-powered root) must be non-negative
2) Any value in a denominator cannot equal 0.<br>

There's no square roots to worry about here, but the middle term, 5/x, has an x in the denominator. This is not defined when x = 0.