2x1-x2+3x3=1, 0=1. 2x1+3x3-X2=1, 7=2<3=n d1-=1≠0.故无解2x1−x2+3x3=1, −x3=2, 0 2x1 +3x3 −x2=1, −x3 =2, 0=1.  r=2 < 3=n. dr+1=10. 故无解. =1