若实数x,y,z,满足:x+1y=1,y+1z=1,则xyz的值为(  ) A.1 B.2 C.-1 D.-2

问题描述:

若实数x,y,z,满足:x+

1
y
=1,y+
1
z
=1,则xyz的值为(  )
A. 1
B. 2
C. -1
D. -2

∵x+

1
y
=1,y+
1
z
=1,
∴x=1-
1
y
=
y−1
y
1
z
=1-y,
∴z=
1
1−y

∴xyz
=
y−1
y
×y×
1
1−y

=-1,
故选C.