What is the domain of f(x)=x−4x2+2x−8f(x) = \frac{x-4}{x^2+2x-8}f(x)=x2+2x−8x−4?
All real numbers except x=4,x=−2x=4, x=-2x=4,x=−2
All real numbers except x=2,x=−4x=2, x=-4x=2,x=−4
All real numbers except x=−2x=-2x=−2
All real numbers except x=4,x=−4x=4, x=-4x=4,x=−4