方程组:X+Y+Z=3.3 X/3+Y/4+X/5=51/60 Z/3+Y/4+X/5=53.4/60

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方程组:X+Y+Z=3.3 X/3+Y/4+X/5=51/60 Z/3+Y/4+X/5=53.4/60

方程组:X+Y+Z=3.3 X/3+Y/4+X/5=51/60 Z/3+Y/4+X/5=53.4/60
方程组:X+Y+Z=3.3 X/3+Y/4+X/5=51/60 Z/3+Y/4+X/5=53.4/60

方程组:X+Y+Z=3.3 X/3+Y/4+X/5=51/60 Z/3+Y/4+X/5=53.4/60
X+Y+Z=3.3 (1)
X/3+Y/4+X/5=51/60 即 20X+15Y+12Z=51 (2)
Z/3+Y/4+X/5=53.4/60 即 12X+15Y+20Z=53.4 (3)
(3)-15*(1)=-3X+5Z=3.9 (4)
(3)-(2)=-8X+8Z=2.4 即-X+Z=0.3 (5)
(4)-3*(5) 2Z=3 Z=1.5
代入(5)得 X=1.2
代入(1) 得Y=0.6

X+Y+Z=3.3
20X+15Y+12Z=51
12X+15Y+20Z=53.4
3X+5Z=3.9
8X+8Z=2.4 X+Z=0.3
2Z=3
Z=1.5
X=1.2
Y=0.6