You can do elementary row operations by multiplying on the left by appropriate elementary matrices, the matrices obtained from an identity matrix by applying the same elementary row operation as you want to perform on your matrix. The technique is illustrated in the following examples.
To create an elementary matrix, choose Fill Matrix from the Matrices submenu; get an identity matrix of the appropriate dimension by making choices in the Fill Matrix dialog box, and perform an elementary row operation by editing the identity matrix. Choose Evaluate to get the following products.
Add λ times row 3 to row 1
=
Interchange rows 2 and 3
=
Multiply row 2 by λ
=