初二计算一题

问题描述:

初二计算一题
(1-2/(x+1))平方/(x-1)/(x+1)

=(-1/(X+1))平方/(X-1)/(X+1)
=(1/(X+1)平方*(X+1)/(X-1)
=(1/(X+1)平方)*(1/(X-1))
=1/(X-1)平方话说。。不能先算减来着..