题型:问答题 —These grapes look really beautiful. —They _______! See the price $3.99 a pound. Very expensive, aren’t they!A.mightB.couldC.would D.should 查看答案
题型:问答题 设方程组 (*) 有通解k1ξ1+k2ξ2=k1[1,2,1,-1]T+k2[0,-1,-3,2]T. 方程组 (**) 有通解 λ1η1+λ2η2=λ1[2,-1,-6,1]T+λ2[-1,2,4,a+8]T. 已知方程组 (***) 有非零解,试确定参数a的值,并求该非零解. 查看答案