x+y+z=3200 (2/3)x+(3/4)y+(4/5)z=2400 (4/5)x+(3/4)y+(2/3)z=2320这道3元一次方程怎么解?
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![x+y+z=3200 (2/3)x+(3/4)y+(4/5)z=2400 (4/5)x+(3/4)y+(2/3)z=2320这道3元一次方程怎么解?](/uploads/image/z/13297308-60-8.jpg?t=x%2By%2Bz%3D3200+%282%2F3%29x%2B%283%2F4%29y%2B%284%2F5%29z%3D2400+%284%2F5%29x%2B%283%2F4%29y%2B%282%2F3%29z%3D2320%E8%BF%99%E9%81%933%E5%85%83%E4%B8%80%E6%AC%A1%E6%96%B9%E7%A8%8B%E6%80%8E%E4%B9%88%E8%A7%A3%3F)
x+y+z=3200 (2/3)x+(3/4)y+(4/5)z=2400 (4/5)x+(3/4)y+(2/3)z=2320这道3元一次方程怎么解?
x+y+z=3200 (2/3)x+(3/4)y+(4/5)z=2400 (4/5)x+(3/4)y+(2/3)z=2320这道3元一次方程怎么解?
x+y+z=3200 (2/3)x+(3/4)y+(4/5)z=2400 (4/5)x+(3/4)y+(2/3)z=2320这道3元一次方程怎么解?
依次将方程记为(1)(2)(3),则(2)-(3)得:
(2/3-4/5)x-(4/5-2/3)z=80,即-x+z=600…(4)
(1)*3/4-(2),并化简,得:5x-3z=0…(5)
解(4)、(5)组成的方程组,得:x=900,z=1500,
代入(1)得:y=800
x+y+z=3200 (1)
(2/3)x+(3/4)y+(4/5)z=2400 (2)
(4/5)x+(3/4)y+(2/3)z=2320 (3)
(1)*3/4-(2) 得一个x,z 方程 (4)
(2)-(3) 得一个x,z 方程 (5)
联立(4) (5)二元一次方程,可以继续消元,解得x,z
代入(1)解得y不...
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x+y+z=3200 (1)
(2/3)x+(3/4)y+(4/5)z=2400 (2)
(4/5)x+(3/4)y+(2/3)z=2320 (3)
(1)*3/4-(2) 得一个x,z 方程 (4)
(2)-(3) 得一个x,z 方程 (5)
联立(4) (5)二元一次方程,可以继续消元,解得x,z
代入(1)解得y
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