PreCalc
posted by Tori on .
I have to solve these using matrices by hand. Can someone please help me?
2x3y2z=4
(1/4)x(2/5)y+(3/4)z=(1/3)
2x+1.3y3z=5
Thank you so much! :)

2x3y2z=4
(1/4)x(2/5)y+(3/4)z=(1/3)
2x+1.3y3z=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 
I used this:
http://www.gregthatcher.com/Mathematics/GaussJordan.aspx 
OMG thanks you so much!