a) (2-3x)/(x²-x)+2/(x-1)+5/3x=
=(2-3x)/x(x-1)+2/(x-1)+5/3x=
=(6-9x+6x+5x-5)/3x(x-1)=
=(1+2x)/3x(x-1)
b) (3x+1)/(2x²-6x)-(x+2)/(3x-9)+(2x-1)/6x=
= (3x+1)/2x(x-3)-(x+2)/3(x-3)+(2x-1)/6x=
= (9x+3-2x²-4x+2x²-x-6x+3)/6x(x-3)=
= (9x+6-11x)/6x(x-3)=
= (-2x+6)/6x(x-3)=
= -2(x-3)/6x(x-3)=
= -1/3x