Question

克莱姆法则解方程组x1+x2+2x3+3x4=4X1+x2+x4=43x1+x2+5x3+10x4=124x1+5x2+

Answer 1

x1+x2+2x3+3x4=4 ①

X1+x2+x4=4 ②

3x1+x2+5x3+10x4=12 ③

4x1+5x2+9x3+13x4=18 ④

由①-②得：x3=-x4

代入③后-②得：x1=4-2x4

代入②得：x2=x4

将 x3=-x4,x1=4-2x4 ,x2=x4

代入④得：x4=2

那么：x3=-x4=-2

x2=x4=2

x1=4-2x4=0