2X+4Y+3Z=9 3X-6Y+5Z=11 5X-6Y+7Z=13
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![2X+4Y+3Z=9 3X-6Y+5Z=11 5X-6Y+7Z=13](/uploads/image/z/1593217-1-7.jpg?t=2X%2B4Y%2B3Z%3D9+3X-6Y%2B5Z%3D11+5X-6Y%2B7Z%3D13)
2X+4Y+3Z=9 3X-6Y+5Z=11 5X-6Y+7Z=13
2X+4Y+3Z=9 3X-6Y+5Z=11 5X-6Y+7Z=13
2X+4Y+3Z=9 3X-6Y+5Z=11 5X-6Y+7Z=13
2X+4Y+3Z=9 (1)
3X-6Y+5Z=11 (2)
5X-6Y+7Z=13 (3)
(1)×3+(2)×2
12X+19Z=49 (4)
(3)-(2)
X+Z=1 (5)
(5)×19-(4)
7X=-30
X=-30/7
Z=1-X=37/7
Y=(9-2X-3Z)/4=3/7
x=-3/2 y=9/4 z=1
2x+4y+3z=9…………①
3x-6y+5z=11…………②
5x-6y+7z=13…………③
②+③得:x+z=1…………④
①×3+② ×2得:12x+19y=49…………⑤
⑤-④×12得:z=37/7
z=37/7代入④得:x=-30/7
把x=-30...
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2x+4y+3z=9…………①
3x-6y+5z=11…………②
5x-6y+7z=13…………③
②+③得:x+z=1…………④
①×3+② ×2得:12x+19y=49…………⑤
⑤-④×12得:z=37/7
z=37/7代入④得:x=-30/7
把x=-30/7, z=37/7代入①得:y=3/7
所以,原方程组的解是: x=-30/7
y=3/7
z=37/7
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