问题
解答题
先化简,再求值:
|
答案
÷(a+1)×a2-1 a2+6a+9 a2-9 a-1
=
×(a+1)(a-1) (a+3)2
×1 a+1 (a+3)(a-3) a-1
=
,a-3 a+3
将a=1代入上式得:
原式=
=a-3 a+3
=-1-3 1+3
.1 2
先化简,再求值:
|
÷(a+1)×a2-1 a2+6a+9 a2-9 a-1
=
×(a+1)(a-1) (a+3)2
×1 a+1 (a+3)(a-3) a-1
=
,a-3 a+3
将a=1代入上式得:
原式=
=a-3 a+3
=-1-3 1+3
.1 2