Add some matrix operations

[kaan2463]

Some Important Matrix Operations:

• Linear System Solver (Gauss Elimination)
• Eigen Value decomposition
• Singular Value Decomposition (SVD)
• QR algorithm
• etc.

[kaan2463]

Actually, it is not needed to implement Linear system solver, because:
For system Ax = y; (A^{-1})Ax = A^{-1}y ==> x =A^{-1}y
so it can be done by using inverse function and inverse function had already been implemented :)