7x-3y+2z=15 6x+2y-z=13 3x-2y+2z=10 【方程组解】
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![7x-3y+2z=15 6x+2y-z=13 3x-2y+2z=10 【方程组解】](/uploads/image/z/1859587-43-7.jpg?t=7x-3y%2B2z%3D15+6x%2B2y-z%3D13+3x-2y%2B2z%3D10+%E3%80%90%E6%96%B9%E7%A8%8B%E7%BB%84%E8%A7%A3%E3%80%91)
7x-3y+2z=15 6x+2y-z=13 3x-2y+2z=10 【方程组解】
7x-3y+2z=15 6x+2y-z=13 3x-2y+2z=10 【方程组解】
7x-3y+2z=15 6x+2y-z=13 3x-2y+2z=10 【方程组解】
7x-3y+2z=15 (1)
6x+2y-z=13 (2)
3x-2y+2z=10 (3)
(1)+2(2)
19x+y=41
(1)-(3)
4x-y=5
23x=46
x=2
y=3
z=5
7x-3y+2z=15,14x-6y+4z=30,
6x+2y-z=13,18x+6y-3z=39,32x+z=69,
3x-2y+2z=10 ,9x+z=23,23x=46,x=2,z=5,y=3
设①7x-3y+2z=15 ②6x+2y-z=13 ③3x-2y+2z=10
①+②×2:(7x-3y+2z)+(6x+2y-z)×2=15+13×2 → 19x+y=41.......④
①-③=(7x-3y+2z)-(3x-2y+2z)=15-10 →4 x-y=5........⑤
④+⑤=(19x+y)+(4x-y)=41+5 ...
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设①7x-3y+2z=15 ②6x+2y-z=13 ③3x-2y+2z=10
①+②×2:(7x-3y+2z)+(6x+2y-z)×2=15+13×2 → 19x+y=41.......④
①-③=(7x-3y+2z)-(3x-2y+2z)=15-10 →4 x-y=5........⑤
④+⑤=(19x+y)+(4x-y)=41+5 → 23x=46→x=2
将x=2代入⑤ → 4×2-y=5 → y=3
将x=2和y=3代入③ → 3×2-2×3+2z=10 → z=5
则x=2 y=3 z=5
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