4 -1 3 12
1 4 6 -32
5 3 9 20
Step 1: Swap row 3 and 1
5 3 9 20
1 4 6 -32
4 -1 3 12
Step 2: Divide row 1 by 5
1 0.6 1.8 4
1 4 6 -32
4 -1 3 12
Step 3: Subtract row 1 from row 2
1 0.6 1.8 4
0 3.4 4.2 -36
4 -1 3 12
Step 4: Subtract (4 × row 1) from row 3
1 0.6 1.8 4
0 3.4 4.2 -36
0 -3.4 -4.2 -4
Step 5: Divide row 2 by 3.4
1 0.6 1.8 4
0 1 1.235 -10.588
0 -3.4 -4.2 -4
Step 6: Subtract (-3.4 × row 2) from row 3
1 0.6 1.8 4
0 1 1.235 -10.588
0 0 0 -40
Step 7: Divide row 3 by -40
1 0.6 1.8 4
0 1 1.235 -10.588
0 0 0 1
Matrix is now in row echelon form
Step 8: Subtract (4 × row 3) from row 1
1 0.6 1.8 0
0 1 1.235 -10.588
0 0 0 1
Step 9: Subtract (-10.588 × row 3) from row 2
1 0.6 1.8 0
0 1 1.235 0
0 0 0 1
Step 10: Subtract (0.6 × row 2) from row 1
1 0 1.059 0
0 1 1.235 0
0 0 0 1
Use Gaussian elimination to find the complete solution to the system of equations, or state that none exists. Show your work.
4x-y+3z = 12
x+4y+6z =-32
5x+3y+9z = 20
...... I NEED HELP WITH THE OTHER TWO PLEASE :)
4 -1 3 | 12
1 4 6 | -32
5 3 9 | 20
1 0 0
0 1 0
0 0 1
4 -1 3 | 12
1 4 6 | -32
5 3 9 | 20
4 -1 3 | 12
4 16 24 | -128
5 3 9 | 20
4 -1 3 | 12
0 17 21 | -140
5 3 9 | 20
4 -1 3 | 12
0 17 21 | -140
20 12 36 | 80
4 -1 3 | 12
0 17 21 | -140
0 17 21 | 20
17y+21z = -140
17y+21z = 20
14 answers
http://www.idomaths.com/gauss_jordan.php
Thats for x+4y+6z =-32 right ?
1 4 6 -32 yes
but your problem gives a very strange answer
but your problem gives a very strange answer
Okay for the 3rd one what am I supposed to put in the boxes ? what numbers ?
You can not reduce the last row to
0 0 1 something
0 0 1 something
You mean this ?
17y+21z = -140
that would be
0 17 21 -140
17y+21z = -140
that would be
0 17 21 -140
Oh so for the last one I don't do anything ?
No I was talking about this one 5x+3y+9z = 20
4x-y+3z = 12
x+4y+6z =-32
5x+3y+9z = 20
We did the first two but not the last one
x+4y+6z =-32
5x+3y+9z = 20
We did the first two but not the last one
Huh,
they are
4 -1 3 12
1 4 6 -32
5 3 9 20
the trouble is that it can not be solved
they are
4 -1 3 12
1 4 6 -32
5 3 9 20
the trouble is that it can not be solved
Okay thank you so much :)
calculate the determinant of the 3 by 3 on the left as if you were going to do Cramer rule
THE DETERMINANT IS ZERO
THE DETERMINANT IS ZERO
Thank you !