Suppose the labelled price for an item is £700. And the seller asks for £600 as his first concession. What is lowest offer that is likely to be accepted by the seller?
【简答题】设有向量组Ⅰ:α 1 =(1,0,2) T ,α 2 =(1,1,3) T ,α 3 =(1,-1,a+2) T 和向量组Ⅱ:β 1 =(1,2,a+3) T ,β 2 =(2,1,a+6) T ,β 3 =(2,1,a+4) T .试问:当a为何值时,向量组Ⅰ与向量组Ⅱ等价?当a为何值时,向量组Ⅰ与向量组Ⅱ不等价?