If f(x)=2x+6x2−9f(x) = \frac{2x+6}{x^2-9}f(x)=x2−92x+6, what is the value of the hole in the graph?
x=3x=3x=3
x=−3x=-3x=−3
x=0x=0x=0
x=−6x=-6x=−6