补充:
5x-4/(x-1)(2x-1)=M/(x-1)-N/(2x-1)
=(2mx-m-nx+n)/(x-1)(2x-1)
=[x(2m-n)-(m-n)]/(x-1)(2x-1)
∴2m-n=5
m-n=4
∴m=1
n=-3