Example 2. Interchange rows 2 and 3 and try to use the Gauss-Jordan subroutine to solve .  
Use lists in the subscript to select rows 2 and 3 and perform the row interchange.

Solution 2.

Then try to perform Gauss-Jordan elimination without row interchanges.

Gauss-Jordan elimination does not work without row interchanges.

(c) John H. Mathews 2004