Calculating a determinant using row-reduction, figuring out if a matrix is invertible. Is the answer really 123? Watch this video and find out! This question was on my linear algebra exam back when I took that class
Check out my Determinants playlist: https://www.youtube.com/playlist?list=PLJb1qAQIrmmDqVlGW1_0JOiiMZzT6-AUE
Subscribe to my channel: https://www.youtube.com/channel/UCoOjTxz-u5zU0W38zMkQIFw