Consider the rational function

g(x)=4x36x2+0x81\displaystyle {g{{\left({x}\right)}}}=\frac{{-{4}{x}-{36}}}{{{x}^{{2}}+{0}{x}-{81}}}

Factor the numerator to get  

Factor the denominator to get  

The rational function f\displaystyle {f} has a vertical asymptote at x=\displaystyle {x}=