解下列方程组:(1)x+2y=9 y-3z=-5 5z-x=14 (2)x:y=3:2 y:z=5:4 x+y+z=66 (3)2x-2y+z=0 2x+y-z=1 x+3y-2z=1解下列方程组:(1)x+2y=9 y-3z=-5 5z-x=14 (2)x:y=3:2 y:z=5:4 x+y+z=66 (3)2x-2y+z=0 2x+y-z=1 x+3y-2z=1 哪怕写一题也好啊

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解下列方程组:(1)x+2y=9 y-3z=-5 5z-x=14 (2)x:y=3:2 y:z=5:4 x+y+z=66 (3)2x-2y+z=0 2x+y-z=1 x+3y-2z=1解下列方程组:(1)x+2y=9 y-3z=-5 5z-x=14 (2)x:y=3:2 y:z=5:4 x+y+z=66 (3)2x-2y+z=0 2x+y-z=1 x+3y-2z=1 哪怕写一题也好啊
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解下列方程组:(1)x+2y=9 y-3z=-5 5z-x=14 (2)x:y=3:2 y:z=5:4 x+y+z=66 (3)2x-2y+z=0 2x+y-z=1 x+3y-2z=1解下列方程组:(1)x+2y=9 y-3z=-5 5z-x=14 (2)x:y=3:2 y:z=5:4 x+y+z=66 (3)2x-2y+z=0 2x+y-z=1 x+3y-2z=1 哪怕写一题也好啊
解下列方程组:(1)x+2y=9 y-3z=-5 5z-x=14 (2)x:y=3:2 y:z=5:4 x+y+z=66 (3)2x-2y+z=0 2x+y-z=1 x+3y-2z=1
解下列方程组:(1)x+2y=9 y-3z=-5 5z-x=14 (2)x:y=3:2 y:z=5:4 x+y+z=66 (3)2x-2y+z=0 2x+y-z=1 x+3y-2z=1 哪怕写一题也好啊

解下列方程组:(1)x+2y=9 y-3z=-5 5z-x=14 (2)x:y=3:2 y:z=5:4 x+y+z=66 (3)2x-2y+z=0 2x+y-z=1 x+3y-2z=1解下列方程组:(1)x+2y=9 y-3z=-5 5z-x=14 (2)x:y=3:2 y:z=5:4 x+y+z=66 (3)2x-2y+z=0 2x+y-z=1 x+3y-2z=1 哪怕写一题也好啊
(1)x+2y=9① y-3z=-5② 5z-x=14③
①+③得:2y+5z=23④
④-②×2得:11z=33,z=3;代入②得:y=4;代入③得:x=1.
(2)x:y=3:2① y:z=5:4② x+y+z=66③
x∶y=3∶2=(3×2.5)∶(2×2.5)=7.5∶5
所以x∶y∶z=7.5∶5∶4
x=66×7.5÷(7.5+5+4)=45
y=66×5÷(7.5+5+4)=20
z=66×4÷(7.5+5+4)=16.
(3)2x-2y+z=0① 2x+y-z=1② x+3y-2z=1③
①+②得:4x-y=1④
①×2+③得:5x-y=1⑤
⑤-④得:x=0,把x=0代入⑤得:y=-1
把x=0、y=-1代入①得:z=-2

(1)
x+2y=9 y-3z=-5 5z-x=14
y-3z=-5→y=3z-5→2y=6z-10→x+6z-10=9→x+6z=19→11z=33→z=3→x=1→y=4

(1)x=1,y=4,z=3
(2)x=30,y=20,z=16
(3)x=-2,y=-1,z=2