Posted by **Tori** on Monday, December 3, 2012 at 2:41am.

I have to solve these using matrices by hand. Can someone please help me?

2x-3y-2z=4

(1/4)x-(2/5)y+(3/4)z=(-1/3)

-2x+1.3y-3z=5

Thank you so much! :)

- Pre-Calc -
**Damon**, Monday, December 3, 2012 at 3:30am
2x-3y-2z=4

(1/4)x-(2/5)y+(3/4)z=(-1/3)

-2x+1.3y-3z=5

==============================

Google Gauss Jordan reduction

use all integers or fractions

2 -3 -2 4

1/4 -2/5 3/4 -1/3

-2 13/10 -3 5

Divide row 1 by 2

1 -3/2 -1 2

1/4 -2/5 3/4 -1/3

-2 13/10 -3 5

Add (-1/4 * row1) to row2

1 -3/2 -1 2

0 -1/40 1 -5/6

-2 13/10 -3 5

Add (2 * row1) to row3

1 -3/2 -1 2

0 -1/40 1 -5/6

0 -17/10 -5 9

Divide row2 by -1/40

1 -3/2 -1 2

0 1 -40 100/3

0 -17/10 -5 9

Add (17/10 * row2) to row3

1 -3/2 -1 2

0 1 -40 100/3

0 0 -73 197/3

Divide row3 by -73

1 -3/2 -1 2

0 1 -40 100/3

0 0 1 -197/219

Add (40 * row3) to row2

1 -3/2 -1 2

0 1 0 -580/219

0 0 1 -197/219

Add (1 * row3) to row1

1 -3/2 0 241/219

0 1 0 -580/219

0 0 1 -197/219

Add (3/2 * row2) to row1

1 0 0 -629/219

0 1 0 -580/219

0 0 1 -197/219

- Pre-Calc -
**Damon**, Monday, December 3, 2012 at 3:44am
I used this:

http://www.gregthatcher.com/Mathematics/GaussJordan.aspx

- Pre-Calc -
**Tori**, Monday, December 3, 2012 at 4:16am
OMG thanks you so much!

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