3x + 2y + z = 3
x - 3y + z = 4
-6x - 4y - 2z = 1
The idea is to get a system that looks like this:
Ax + By + Cz = D
Ey + Fz = G
Hz = I
And it's OK if the + signs are minuses.
Get rid of the x by multiplying the 2nd eq by -3
and adding the first equation to it:
3x + 2y + z = 3
-3x + 9y - 3z = -12
-------------------
11y - 2z = -9
So the system is now:
3x + 2y + z = 3
11y - 2z = -9
-6x - 4y - 2z = 1
Get rid of the -6x by multiplying the 1st eq by 2
and adding the third equation to it:
6x + 4y + 2 = 6
-6x - 4y - 2z = 1
-------------------
0z = 7
We can stop right here and say there is no solution,
because no value of z multiplied by zero can give 7.
So we write:
No solution, the equations are inconsistent.
Edwin