已知:x=1- 2 ,y=1+ 2 ,求 ( 1 x+y + 1 x-y )÷ 2x

已知:x=1- 2 ,y=1+ 2 ,求 ( 1 x+y + 1 x-y )÷ 2x x 2 -2xy+ y 2 的值.
2025-05-19 14:05:18
推荐回答(1个)
回答1:

原式=
x-y+x+y
(x-y)(x+y)
×
(x-y) 2
2x

=
2x
(x-y)(x+y)
×
(x-y) 2
2x

=
x-y
x+y

当x=1-
2
,y=1+
2
时,
原式=
1-
2
-1-
2
1-
2
+1+
2
=
-2
2
2
= -
2