Hi,

I need guidance with the following question:

Question: Reduce the matrix [A|I] in order to determine if A is invertible. Compute A^-1 when A is invertible and check that AA^-1 = I. Verify that the (1,1)-entry in the product A^-1 is 1.

A=

2 1

5 3

For starters,I was going to find the determinant of A like this: |A|= ad-bc, but realized the question is asking me to reduce the matrix [A|I]. So how do I reduce [A|I]? Do I multiply matrix A * Identity matrix, then use reduced row echelon like this:

2 1|1 0

5 3|0 1