题目 7.用克莱姆法则解线性方程组-|||- ) (x)_(1)+(x)_(2)+(x)_(3)+(x)_(4)=5 (x)_(1)+2(x)_(2)-(x)_(3)+4(x)_(4)=-2 2(x)_(1)-3(x)_(2)-(x)_(3)-5 . 题目解答答案