问题
解答题
设xyz=1,求
|
答案
原式=
+x xy+x+1
+xy xyz+xy+x
,z zx+z+1
=
+x xy+x+1
+xy 1+xy+x
,zxy zx•xy+zxy+xy
=
+x xy+x+1
+xy xy+x+1
,1 xy+x+1
=
,xy+x+1 xy+x+1
=1.
设xyz=1,求
|
原式=
+x xy+x+1
+xy xyz+xy+x
,z zx+z+1
=
+x xy+x+1
+xy 1+xy+x
,zxy zx•xy+zxy+xy
=
+x xy+x+1
+xy xy+x+1
,1 xy+x+1
=
,xy+x+1 xy+x+1
=1.