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x,y,z为正实数,且满足xyz=1,x+1y=5,y+1z=29,则z+1x的值为1414.

题目详情
x,y,z为正实数,且满足xyz=1,x+
1
y
=5,y+
1
z
=29,则z+
1
x
的值为
1
4
1
4
▼优质解答
答案和解析
(x+
1
y
)(y+
1
z
)(z+
1
x

=(x+y+z)+xyz+
1
xyz
+(
1
x
+
1
y
+
1
z

=2+(x+
1
y
)+(y+
1
z
)+(z+
1
x
),
∴5×29×(z+
1
x
)=36+(z+
1
x
),
  即 z+
1
x
=
1
4

故答案为:
1
4