I'm studying systems of linear equations.
I'm now specifically studying systems of linear equations of the 1st order, homogeneous:
$Y' = AY$
$A$ as a constant matrix.
Now I know there are various methods to solve this systems. My professor talked about one of the method that consists on reducing the system into a single equation. Does anyone knows where can I find notes or explanations about how to apply correctly this method? I'm having trouble finding it on the internet. I find a lot of things about the method that uses eigenvalues/eigenvectors but that's a method that my professor doesn't like... Does anyone know a good text that I can look for?