关于方程组_(1)-2(x)_(2)+3(x)_(3)-4(x)_(4)=4 _(1)-2(x)_(2)+3(x)_(3)-4(x)_(4)=4 _(1)-2(x)_(2)+3(x)_(3)-4(x)_(4)=4下列说法正确的是（）

求线性方程组_(1)+(x)_(2)+(x)_(3)+(x)_(4)=0-|||-_(2)+2(x)_(3)+2(x)_(4)=1-|||-_(1)+2(x)_

例4 讨论线性方程组-|||- ) (x)_(1)+(x)_(2)+2(x)_(3)+3(x)_(4)=1 (x)_(1)+3(x)_(2)+6(x)_(3)

求非齐次线性方程组 ) (x)_(1)+(x)_(2)-3(x)_(3)-(x)_(4)=1 3(x)_(1)-(x)_(2)-3(x)_(3)+4(x)_(

1.已知方程组 ) (x)_(1)+(x)_(2)+(x)_(3)+(x)_(4)=2 3(x)_(1)+2(x)_(2)+(x)_(3)+(x)_(4)=a

3.求解线性方程组 ) (x)_(1)+2(x)_(2)-(x)_(3)+2(x)_(4)=1 2(x)_(1)+4(x)_(2)+(x)_(3)+(x)_(

设非齐次线性方程组 ) (x)_(1)+2(x)_(3)+(x)_(4)=2 (x)_(1)+(x)_(2)+(x)_(3)+4(x)_(4)=a (x)_(

2.解方程组 ) (x)_(1)+(x)_(2)+(x)_(3) (x)_(1)+(x)_(2)-(x)_(3)-(x)_(4)=1 5(x)_(1)+5(

线性方程组 ) (x)_(1)+2(x)_(2)-2(x)_(3)=1 2(x)_(1)+4(x)_(2)-4(x)_(3)=2 3(x)_(1)+6(x)_

如果线性方程组 ) 3(x)_(1)+k(x)_(2)-(x)_(3)=1 4(x)_(2)-(x)_(3)=2 4(x)_(2)+k(x)_(3)=3 .

用克莱姆法则解线性方程组 x2-3x3+4x4=-5 x1-2x3+3x4=-4 3x1+2x2-5x4=12 4x1+用克莱姆法则解线性方程组 x2-3x3+