x根号(yz)+y根号(xz)=39-xy y根号(xz)+z根号(xy)=52-yz z根号(xy)+x根号(yz)=78-xz
x根号(yz)+y根号(xz)=39-xy y根号(xz)+z根号(xy)=52-yz z根号(xy)+x根号(yz)=78-xz
x√(yz)+y√(xz)=39-xy =>√(xy)*[√(xy)+√(xz)+√(yz)]=39 (1)
y√(xz)+z√(xy)=52-yz =>√(yz)*[√(yz)+√(xy)+√(xz)]=52 (2)
z√(xy)+x√(yz)=78-xz =>√(xz)*[√(xz)+√(yz)+√(xy)]=78 (3)
(1)+ (2)+ (3)可得
√(xz)+√(yz)+√(xy)=13 (4)
把(4)代人(1)(2)(3)分别可得
√(xy)=3 ∴xy=9
√(yz)=4 ∴yz=16
√(xz)=6 ∴xz=36
将上面三式相乘可得
xyz=3x4x6再除以上面三式于是可得,x=9/2, y=2, z=8
x√(yz)+y√(xz)=39-xy => xy+x√(yz)+y√(xz)=√(xy)*[√(xy)+√(xz)+√(yz)]=39 (1)
y√(xz)+z√(xy)=52-yz => yz+y√(xz)+z√(xy)=√(yz)*[√(yz)+√(xy)+√(xz)]=52 (2)
z√(xy)+x√(yz)=78-xz => xz+z√(xy)+x√(yz)=√(xz)*[√(xz)+√(yz)+√(xy)]=78 (3)
(1)/(2), => √(x/z)=39/52=3/4 (4)
(2)/(3), => √(y/x)=52/78=2/3 (5)
(1)/(3), => √(y/z)=39/78=1/2 (6)
(4)*(6) => √(xy)=3/8*z, (7)
(4)*z => √(xz)=3/4*z, (8)
(6)*z => √(yz)=1/2*z (9)
将(7),(8),(9)代入(1),得 3/8*z[3/8*z+3/4*z+1/2*z]=39
可解得 z=8,再由(8), (9) 解得 x=9/2, y=2
∴ 方程的解为 x=9/2, y=2, z=8