Find inverse, by elementary row operations (if possible), of the following matrices.


Let A =


To apply elementary row transformations we write:


A = IA where I is the identity matrix


We proceed with operations in such a way that LHS becomes I and the transformations in I give us a new matrix such that


I = XA


And this X is called inverse of A = A-1


So we have:



Applying R2 R2 + 5R1



Applying R2 (1/22)R2



Applying R1 R1 – 3R2



As we got Identity matrix in LHS.


A-1 =


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