So I have the matrix

1 0 1 0

0 1 0 1

-2 1 1 0

0 0 1 1

I chose row 3 column 2 and will take it's minor. The minor is

1 1 0

0 0 1

0 1 1

Row two has the most zeros, and so I will select row 2. This leaves me to calculate only row 2 column 3. Which is

1 1

0 1

If I'm not mistaken, the determinant should be 1.

From the 4x4 matrix I have (-1)^3+2 * 1 = 1

From the 3x3 I have only (-1)^2+3 * 1 = 1

All of this just ends up as 1. Am I correct?