问题
解答题
先化简,再求值:
|
答案
原式=
-(x+1)2 (x+1)(x-1) 1 x-1
=x2+2x+1-x-1 (x+1)(x-1)
=x x-1
当x=
+1时,2
原式=
+12 2
=
(2+1 2
)2
=1+2 2
先化简,再求值:
|
原式=
-(x+1)2 (x+1)(x-1) 1 x-1
=x2+2x+1-x-1 (x+1)(x-1)
=x x-1
当x=
+1时,2
原式=
+12 2
=
(2+1 2
)2
=1+2 2