1-(x-3)/(x-1)怎样变成2/(x-3)?

问题描述:

1-(x-3)/(x-1)怎样变成2/(x-3)?

不可能啊
1-(x-3)/(x-1)=[(x-1)/(x-1)]-[(x-3)/(x-1)]
=[(x-1))-(x-3)]/(x-1)
=2/(x-1)