Question 1007512
We can factor the denominator in order to determine what values of x make it go to zero and are thus disallowed, not being part of the domain...
f(x) = x - 7 / x^3 - 7x^2 - 100x + 700
f(x) = (x - 7) / (x - 10)(x + 10)(x - 7)
Thus the domain is all real except x = 7, 10, and -10.
The x = 7 is what is called a removable discontinuity (if you need to know that).