Question

解线性方程组 x1+2x2+3x3+4x4=5 2x1+4x2+4x3+6x4=8 -x1-2x2-x3-2x4= -？

Answer 1

x1+2x2+3x3+4x4=5 (1)
2x1+4x2+4x3+6x4=8 (2)
-x1-2x2- x3-2x4=-3 (3)
(1)+(3)
2x1+4x2+4x3+6x4=8 = equation(2)
Rank of system of equtions = 2
(1)+2(3)
-x1-2x2+x3=-1
x3= x1+2x2-1 (4)
sub (4) into (3)
-x1-2x2- (x1+2x2-1)-2x4=-3
x4= -x1-2x2 +2
solution of system of equations
(x1,x2,x1+2x2-1,-x1-2x2 +2)
x1,x2属于R,10,可以用矩阵解答吗谢谢了,x1+2x2+3x3+4x4=5 (1)
2x1+4x2+4x3+6x4=8 (2)
-x1-2x2- x3-2x4=-3 (3)
(1)+(3)
2x1+4x2+4x3+6x4=8 = equation(2)
Rank of system of equtions = 2
(1)+2...,1,解线性方程组 x1+2x2+3x3+4x4=5 2x1+4x2+4x3+6x4=8 -x1-2x2-x3-2x4= - 3