用换元法解分式方程6/x²+2x-3 - 18/x²+2x+1 = 0
问题描述：
用换元法解分式方程6/x²+2x-3 - 18/x²+2x+1 = 0
6/x²+2x-3- 18/x²+2x+1 = 0
答
令x²+2x-1=y
则原方程为1/(y-2)-3/(y+2)=0
y+2-3y+6=0
-2y+8=0
y=4
∴x²+2x-1=4
x²+2x-5=0
(x+1)²=6
x+1=±√6
x=-1±√6