In an exercise in my linear algebra book, I'm supposed to find all the co-factors for the matrix:
1 -2 3
6 7 -1
-3 1 4
I've got all of them right, except C31, and C32.
The answers I got, were:
C31 = 23, C32 = -17
According to the book, the correct answer is:
C31 = -19, C32 = 19
Am I wrong or is there an error in the book?