Question

calculate the product of the entries in the third row of the inverse of the matrix
1 2 3
2 3 4
3 1 2

Answer 1

Do you know how to find the inverse of that matrix?

Answer 2

doesnt it pretty much amount to the row reduction of: (A | I) into ( I | A^-1) ?

Answer 3

there is a cofactor method, but it tends to take longer