设a,b,c,d,e为4维列向量,且4阶行列式|a,b,c,d|=5,|a,b,c,e|=7则|a,b,c,3d-e|=
问题描述:
设a,b,c,d,e为4维列向量,且4阶行列式|a,b,c,d|=5,|a,b,c,e|=7则|a,b,c,3d-e|=
答
|a,b,c,3d|= 3x5=15 |a,b,c,3d-e| = |a,b,c,3d| - |a,b,c,e| = 15-7 = 8