Question

解分式方程x-1/x+1 - x/x-1 = 4/(x乘x)-1

Answer 1

(x-1)/(x+1)-x/(x-1)=4/(x^2-1)

去分母

(x-1)^2-x(x+1)=4

整理,得

x+1=0

x=-1

代回去验证,x=-1时,分母x+1和x^2-1均=0,舍去.

方程无解.