问题
解答题
先化简，再求值(
|
答案
原式=
×2(a-1)-(a+1) (a+1)(a-1) (a+1)(a-1) a
=
×a-3 (a+1)(a-1)
=(a+1)(a-1) a
；a-3 a
当a=2时，原式=
=a-3 a
=-2-3 2
．1 2
搜题请搜索小程序“爱下问搜题”
先化简，再求值(
|
原式=
×2(a-1)-(a+1) (a+1)(a-1) (a+1)(a-1) a
=
×a-3 (a+1)(a-1)
=(a+1)(a-1) a
；a-3 a
当a=2时，原式=
=a-3 a
=-2-3 2
．1 2