Gauss Jordan Elimination on Casio 9860 GII

Method 2 using the catalog
To find the solution of a system of equations (using Gauss-Jordan Elimination) on Casio
Press Menu 1
F3, F3
Type # of rows, EXE type # of columns EXE, EXE
Enter values pressing EXE after each
Exit, Exit
Shift, 4, EXE, Shift, 2, Alpha X,Θ,T, EXE

[jayrobbo]

I got a ‘Dimension Error’. Is that because A is not defined? If so how do I do that?