4/(x-1)-1/(2x-1)-2
=4(2x-1)/(x-1)(2x-1)-(x-1)/(x-1)(2x-1)-2(x-1)(2x-1)/(x-1)(2x-1)
=(8x-4-x+1-4x²+6x-2)/(x-1)(2x-1)
=(-4x²+13x-5)/(x-1)(2x-1)