已知实数a满足a2+2a-8=0，则1/a+1−a+3/a2−1×a2−2a+1(a+1)(a+3)=_．
问题描述：
已知实数a满足a2+2a-8=0，则
−1 a+1
×a+3
a2−1
=______．
a2−2a+1 (a+1)(a+3)
答
原式=
-1 a+1
•a+3 (a+1)(a−1)
(a−1)2 (a+1)(a+3)
=
-1 a+1
a−1 (a+1)2
=
a+1−(a−1) (a+1)2
=
，2
a2+2a+1
∵a2+2a-8=0，
∴a2+2a=8，
∴原式=
=2 8+1
．2 9
故答案为
．2 9