Systems of Linear Equations (Part II)

We can always use Gaussian Elimination to reduce an augmented matrix to row echelon form (r.e.f.).

If a linear system has r(A) = r([A|b]) < n, how many solutions does the system have?

Pick all the correct answers.

All SQUARE matrices are invertible.

I use _______ to further reduce a matrix to reduced row echelon form (r.r.e.f.).

I can solve for the infinitely many solutions of a homogeneous system using different ways, except ______.