怎样解方程组{2x+y+z=5,x-y+2z=4,3x+2y-3z=3

问题描述:

怎样解方程组{2x+y+z=5,x-y+2z=4,3x+2y-3z=3

2x+y+z=5①
x-y+2z=4②
3x+2y-3z=3 ③
①+②推出3x+3z=9④
②x2+③推出5x+z=11⑤
⑤x3-④推出x=2代入⑤
得z=1,y=0