1) 1/x-1 - x+2/3x^2-3x

2) x+1/x-x^2 + x/x^2-1

3) 2x^2/x-1 - 2x

1) 1 / (x-1) - (x+2) / (3x²-3x) = 1 / (x-1) - (x+2) / (3x (х-1)) = (3 х-х-2) / (3 х (х-1)) = 2 (х-1) / 3 х (х-1) = 2/3 х.

2) (x+1) / (x-x²) + x / (x²-1) = (x+1) / x (1-х) + x / (x-1) (х+1) = - (x+1) (х+1) + х²/x (x-1) (х+1) = (-х²-2 х-1+х²) / (х³-х) = (-2 х-1) / (х³-х)

3) 2x ² / (x-1) - 2x = (2 х ²-2 х²+2 х) / (х-1) = 2 х / (х-1)