两道初中数学题(1)化简分式(x^2-1/x^2+2x+1)-(x+1/x-1)
问题描述:
两道初中数学题(1)化简分式(x^2-1/x^2+2x+1)-(x+1/x-1)
(2)解方程(x-1/x)-(x/x-1)=5/2
答
(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=2.5...