Question 107458
You need to factor the numerator first.
{{{x^2-6x+8=(x-4)(x-2)}}}
and substitute.
{{{(x^2-6x+8)/(x-4)=((x-4)(x-2))/((x-4))}}}
{{{(x^2-6x+8)/(x-4)=(x-2)}}}