若是[x(x-3)]/(x^2+2)=0,则解如下：
∵x(x-3)/(x^2+2)=0
∴x(x-3)=0
解之得：x=0,x=3
∴当x=0时,[2x/(x^2-1)]/[2x/(1-x)]无解.
当x=3时,[2x/(x^2-1)]/[2x/(1-x)]=-1/(x+1)
=-1/4
若x=1/x,则x=1
∴x-1=0
∴[(x^2+2x-3)/(x-1)]/[(x+2)/(x^2-3x+1)]无解
最后一题,已知条件看不懂.