来自刘又诚的问题
解方程组z=x+y2x-3y+2z=5x+2y-z=3
解方程组z=x+y2x-3y+2z=5x+2y-z=3
1回答
2020-05-31 08:48
解方程组z=x+y2x-3y+2z=5x+2y-z=3
解方程组z=x+y2x-3y+2z=5x+2y-z=3
x+y-z=0(1)
x+2y-z=3(2)
2x-3y+2z=5(3)
2-1式得y=3
将y=3代入2、3得
x-z=-3(4)
x+z=7(5)
4+5式得2x=4解得x=2y=5
综合得x=2y=3z=5