x/x-2 - x+1/x = 8/x^2-2x
notice the last denominator factors to x(x-2) and those factors are found in the other two fractions
so x(x-2) is the lowest common denominator.
now multiply each term by that x(x-2) to get
(x)(x) -(x+1)(x-2) = 8
simplify and solve
I got x=6