第1个回答 2019-04-16
（1）化简分式(x^2-1/x^2+2x+1)-(x+1/x-1)
=(x+1)(x-1)/(x+1)^2-(x+1)/(x-1)=(x-1)/(x+1)-(x+1)/(x-1)=[(x-1)^2-(x+1)^2]/(x+1)(x-1)=-4x/(x+1)(x-1)（2）解方程(x-1/x)-(x/x-1)=5/2
(x-1)^2-x^2=5/2x(x-1)-2x+1=2.5x^2-2.5x2.5x^2-0.5x-1=05x^2-x-2=0x^2-x/5=2/5(x-1/10)^2=2/5+1/100=41/100x-1/10=(+/-)根号41/10X1=(1+根号41)/10X2=(1-根号41)/10检验,X1,X2是方程的根.