: (a1,a2,a3) =1 2 13 1 -16 2 a2 -1 -2r3-2r2, r2-r1-r4, r4-2r11 2 10 0 00 0 a+20 -5 -4-->1 2 10 -5 -40 0 a+20 0 0因为向量组线性相蔽喊胡关渗铅, 所以宏拦 a=-2
