[tex]f(x)=\frac{2x^2-7x+6}{x^2-9x+20}\\ f(x)=\frac{(2x-3)(x-2)}{(x-5)(x-4)}\\\\[/tex]
Therefore, the value of x must not be either 5 or 4 which will give the undefined answer.
Therefore, the domain is x<4, x>5 or R - {4,5}
