Thread: gauss jordan help

Ok here I am working on this problem for like 3 hours to no avail.

x1 + x2 = 1
-x1 + x2 + x3 = -1
-1x2 + x3 = 3


I am trying to solve this in matrix form and get the point of multiplaying a cooefficiant but applying it to this set is baffling my mind. Any insights?

is the matrix

1 1 0
-1 1 0
0 -1 1

Originally Posted by wonderstrike

Ok here I am working on this problem for like 3 hours to no avail.

x1 + x2 = 1
-x1 + x2 + x3 = -1
-1x2 + x3 = 3


I am trying to solve this in matrix form and get the point of multiplying a coefficient but applying it to this set is baffling my mind. Any insights?

is the matrix

1 1 0
-1 1 0
0 -1 1

You should use an "augmented" matrix, with an extra column consisting of the coefficients on the right=hand side of the equations. So the matrix is . Now apply the Gauss–Jordan process to the matrix, and then you should be able to read off the solution.

have I broken this down right? so the answer would be the last column 2,-1,2

?

Originally Posted by wonderstrike

have I broken this down right? so the answer would be the last column 2,-1,2

?

That is correct (as you could check for yourself by substituting 2, –1, 2 for in the original equations).