x+y-z=0 2x-y+3z=-1 x+2y+3z=4 解三元一次方程组
问题描述:
x+y-z=0 2x-y+3z=-1 x+2y+3z=4 解三元一次方程组
答
x+y-z=0…………………①2x-y+3z=-1………………②x+2y+3z=4………………③由方程①可得z=x+y………………………④④代入方程②2x-y+3(x+y)=-15x+2y=-1…………⑤④代入方程③x+2y+3(x+y)=44x+5y=4………………...