k1(1,1,1)+k2(-1,0,1)+k3(-1,1,0)=0=>k1-k2-k3=0 (1) andk1 +k3=0 (2) andk1+k2 =0 (3) (1)+(2)2k1-k2=0k2=2k1 (4)sub (4) into (3)3k1=0k1=0 (5)from (4)k2=k1=0 (6)sub (5) (6)into (1)k3=0k1=k2=k3=0=> （1,1,1）...