已知下列两个方程组3x+y+2z=10 x+y+z=6 2x+3y-z=9 与2ax—+2by+cz=6 3ax+5by+3cz已知下列两个方程组3x+y+2z=10 x+y+z=6 2x+3y-z=9 与2ax+2by+cz=6 3ax+5by+3cz=10 4ax-3by+2ca=-9有相同的解求a.b.c的值
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![已知下列两个方程组3x+y+2z=10 x+y+z=6 2x+3y-z=9 与2ax—+2by+cz=6 3ax+5by+3cz已知下列两个方程组3x+y+2z=10 x+y+z=6 2x+3y-z=9 与2ax+2by+cz=6 3ax+5by+3cz=10 4ax-3by+2ca=-9有相同的解求a.b.c的值](/uploads/image/z/3676998-30-8.jpg?t=%E5%B7%B2%E7%9F%A5%E4%B8%8B%E5%88%97%E4%B8%A4%E4%B8%AA%E6%96%B9%E7%A8%8B%E7%BB%843x%2By%2B2z%3D10+x%2By%2Bz%3D6+2x%2B3y-z%3D9+%E4%B8%8E2ax%E2%80%94%2B2by%2Bcz%3D6+3ax%2B5by%2B3cz%E5%B7%B2%E7%9F%A5%E4%B8%8B%E5%88%97%E4%B8%A4%E4%B8%AA%E6%96%B9%E7%A8%8B%E7%BB%843x%2By%2B2z%3D10+x%2By%2Bz%3D6+2x%2B3y-z%3D9+%E4%B8%8E2ax%2B2by%2Bcz%3D6+3ax%2B5by%2B3cz%3D10+4ax-3by%2B2ca%3D-9%E6%9C%89%E7%9B%B8%E5%90%8C%E7%9A%84%E8%A7%A3%E6%B1%82a.b.c%E7%9A%84%E5%80%BC)
已知下列两个方程组3x+y+2z=10 x+y+z=6 2x+3y-z=9 与2ax—+2by+cz=6 3ax+5by+3cz已知下列两个方程组3x+y+2z=10 x+y+z=6 2x+3y-z=9 与2ax+2by+cz=6 3ax+5by+3cz=10 4ax-3by+2ca=-9有相同的解求a.b.c的值
已知下列两个方程组3x+y+2z=10 x+y+z=6 2x+3y-z=9 与2ax—+2by+cz=6 3ax+5by+3cz
已知下列两个方程组3x+y+2z=10 x+y+z=6 2x+3y-z=9 与2ax+2by+cz=6 3ax+5by+3cz=10 4ax-3by+2ca=-9有相同的解求a.b.c的值
已知下列两个方程组3x+y+2z=10 x+y+z=6 2x+3y-z=9 与2ax—+2by+cz=6 3ax+5by+3cz已知下列两个方程组3x+y+2z=10 x+y+z=6 2x+3y-z=9 与2ax+2by+cz=6 3ax+5by+3cz=10 4ax-3by+2ca=-9有相同的解求a.b.c的值
3x+y+2z=10 ①
x+y+z=6 ②
2x+3y-z=9 ③
∴①-2×②得 x-y=-2 ④
③+②得 3x+4y=15 ⑤
∴⑤+4×④得 7x=7
∴x=1代入④得 y=3
∴z=2
∴将x=1,y=3,z=2代入另一个方程组,得到
2a+6b+2c=6 ⑥
3a+15b+6c=10 ⑦
4a-9b+4c=-9 ⑧
∴⑦-3×⑥得 -3a-3b=-8 ⑨
⑧-2×⑥得 -21b=-21 (10)
∴b=1
∴a=5/3
∴c=-5/3
和那个二元的方程一样的方法,先解出XYZ带入二式就解出abc
已知下列两个方程组3x+y+2z=10 x+y+z=6 2x+3y-z=9 与2ax+2by+cz=6 3ax+5by+3cz=10 4ax-3by+2ca=-9有相同的解求a.b.c的值