Linear Algebra and Its Applications · Problem 1.3.16
Matrices and Gaussian Elimination — Gilbert Strang
Mathematics · gaussian-elimination
Problem
Construct a 3 by 3 example that has 9 different coefficients on the left-hand side, but rows 2 and 3 become zero in elimination. How many solutions to your system with b=(1,10,100) and how many with b=(0,0,0)?