Matrices on the TI83
101 in the TI83 Guidebook
The TI series calculator performs numerous matrix operations. This example shows Gaussian Elimination. The function rref is a easy way to find the reducerow echelon form of any size matrix. (up to 99 rows) It has many applications in this book.
Press . Press to display the MATRX EDIT menu. Press 1 to select 1:[A].  
Press 3 4 to define a 3×4 matrix. (3 rows, 4 columns) The rectangular cursor indicates the current element. Ellipses (...) indicate additional columns beyond the screen.  
We want to enter the coefficients into our matrix. Press 3 6 9 0 for the first row. Press 4 6 8 4 for the second row. Press 2 1 1 7 for the third row. 

Press [QUIT] to return to the home screen. If necessary press to clear the home screen.  
Press to display the MATRX MATH menu. Press to wrap to the end of the menu. Select B:rref . ( "reducedrow echelon form")  
Press 1 to select 1:[A] from the MATRX NAMES menu. Press . The reducedrow echelon form of the matrix is displayed aand stored in Ans.  x = 3 

