解:
x1+x2+ x3+ x4+ x5=7
3x1+x2+2x3+ x4- 3x5=-2
2x2+ x3+2x4+6x5=23
1 1 1 1 1
係數矩陣A= 3 1 2 1 -3
0 2 1 2 6
1 1 1 1 1 7
增廣矩陣B=(A,b)= 3 1 2 1 -3 -2
0 2 1 2 6 23
r2-3r1得
0 -2 -1 -2 -6 -23
r3+r2得
0 0 0 0 0 0
-(1/2) r2得
0 1 1/2 1 3 23/2
r1-r2得
1 0 1/2 0 -2 -9/2
所以方程組的通解為x1=-9/2-x3/2+2x5
x2=23/2-x3/2-x4-3x5【x3,x4,x5為任意實數】
解:
x1+x2+ x3+ x4+ x5=7
3x1+x2+2x3+ x4- 3x5=-2
2x2+ x3+2x4+6x5=23
1 1 1 1 1
係數矩陣A= 3 1 2 1 -3
0 2 1 2 6
1 1 1 1 1 7
增廣矩陣B=(A,b)= 3 1 2 1 -3 -2
0 2 1 2 6 23
r2-3r1得
1 1 1 1 1 7
0 -2 -1 -2 -6 -23
0 2 1 2 6 23
r3+r2得
1 1 1 1 1 7
0 -2 -1 -2 -6 -23
0 0 0 0 0 0
-(1/2) r2得
1 1 1 1 1 7
0 1 1/2 1 3 23/2
0 0 0 0 0 0
r1-r2得
1 0 1/2 0 -2 -9/2
0 1 1/2 1 3 23/2
0 0 0 0 0 0
所以方程組的通解為x1=-9/2-x3/2+2x5
x2=23/2-x3/2-x4-3x5【x3,x4,x5為任意實數】