Because the degree of the top is the same as the degree of the bottom you have to simplify one of two ways. One way in by doing long division. The second way is to make the part of the top match the bottom and then split it into 2 fractions.
I will do it the 2nd way.
1st subtract and add 4 to the top. giving us
(x-4+4+2)/(x-4) then split it into to fractions
(x-4)/(x-4)+(4+2)/(x-4) then reduce the 1st fraction to 1 and add on the top of the 2nd.