# [SOLVED] Solutions of four linear systems

• January 14th 2010, 10:55 AM
thekrown
[SOLVED] Solutions of four linear systems
I'm having trouble reading this matrix:

1 0 0 4 -1
0 1 0 2 6
0 0 1 3 2

x1 = -1
x2 = 6
x3 = 2

Is this correct? The 4,2,3 column confuses me.
• January 14th 2010, 12:21 PM
bletchley
Looks like an augmented matrix to me. A matrix of that form generally represents 3 equations with 4 variables.

$
1x_1 + 0x_2 + 0x_3 + 4x_4 = -1
$

$
0x_1 + 1x_2 + 0x_3 + 2x_4 = 6
$

$
0x_1 + 0x_2 + 1x_3 + 3x_4 = 2
$
• January 14th 2010, 12:42 PM
thekrown
Yes indeed, it had slipped my mind. I totally forgot to isolate the x1,2,3 and bring the free variable to the other side. Thank you.