- #1
late347
- 301
- 15
Homework Statement
system of equations is as follows
x+y=1
2x+y-z=1
3x+y-2z=1
##\begin{cases} x+y=1 |*(-1)\\2x+y-z=1\\3x+y-2z=1 \end{cases}##
Homework Equations
Gaussian elimination method technique
The Attempt at a Solution
##\begin{cases} x+y=1 \\ x-z=0 |*(-2)\\ 2x-2z=0 \end{cases}##<=>
##\begin{cases} x+y=1 |*(-1)\\ x-z=0 \\ 0=0 \end{cases}##
<=>
##\begin{cases} x+y=1 \\ -y-z=-1 \\ x=z \end{cases}##
<=>
at this stage I think you are supposed to plug in x=z into some equation in the system
##\begin{cases} x+y=1 \\ -y-z=-1 \\ x=z \end{cases}##
##\begin{cases} x+y=1 <=> x=1-y \\ -y-z=-1 \\ x=z \end{cases}##
##-y-x=-1##
<=> x=-y+1
from those two equations it can be seen that those equations at least are identical equations for the same line.
So I think ultimately based on that geometry there should be infinite solutions (is that the correct way to do it and solve it?)