2x+5y+4z=0 4x+10y+8z=0 (1)3x+y-7z=09x+3y-21z=0 (2)(1)+(2)13(x+y-z)=0x+y-z=0
=0 用2次消元法....算出x=-3/2y z=-1/2y 答案就是0
3
0
是0