x,y,z为实数,且xy/x+y=1/3,yz/y+z=1/4,xz/x+z=1/5,求xyz/xy+yz+zx的值
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![x,y,z为实数,且xy/x+y=1/3,yz/y+z=1/4,xz/x+z=1/5,求xyz/xy+yz+zx的值](/uploads/image/z/173320-16-0.jpg?t=x%2Cy%2Cz%E4%B8%BA%E5%AE%9E%E6%95%B0%2C%E4%B8%94xy%2Fx%2By%3D1%2F3%2Cyz%2Fy%2Bz%3D1%2F4%2Cxz%2Fx%2Bz%3D1%2F5%2C%E6%B1%82xyz%2Fxy%2Byz%2Bzx%E7%9A%84%E5%80%BC)
x,y,z为实数,且xy/x+y=1/3,yz/y+z=1/4,xz/x+z=1/5,求xyz/xy+yz+zx的值
x,y,z为实数,且xy/x+y=1/3,yz/y+z=1/4,xz/x+z=1/5,求xyz/xy+yz+zx的值
x,y,z为实数,且xy/x+y=1/3,yz/y+z=1/4,xz/x+z=1/5,求xyz/xy+yz+zx的值
将xy/x+y=1/3,yz/y+z=1/4,xz/x+z=1/5的分子分母倒一下,可以得到下面的等式:
(1/x)+(1/y)=3 ①
(1/y)+(1/z)=4 ②
(1/z)+(1/x)=5 ③
将①②③相加,得到(1/x)+(1/y)+(1/z)=6 ④
将④通分就可得到xy+yz+zx/xyz = 6
所以xyz/xy+yz+zx = 1/6