Introduction - If you have any usage issues, please Google them yourself
Chapter 3. The Solution of Linear Systems AX = B
Algorithm 3.1 Back Substitution
Algorithm 3.2 Upper-Triangularization Followed by Back Substitution
Algorithm 3.3 PA = LU Factorization with Pivoting
Algorithm 3.4 Jacobi Iteration
Algorithm 3.5 Gauss-Seidel Iteration