Hii. I just found your blog and thanks god, because I was trying to solve this one without luck. It says find the determinant of square matrix A. Thank you so much if you could help
The determinant is invariant under row addition, so if you add row i to row j k times then the determinant doesn’t change.
Knowing that, add row 1 to row 3 4 times and you get that row 3 is full of zeros. This means the determinant is 0.
Hope this helps! @colour-mind