Chapter 3.4, Problem 4EQ

In Exercises 1 -6, solve the system Ax = b using the given LU factorization of A.

$A=\left[\begin{array}{ccc}2& -4& 0\\ 3& -1& 4\\ -1& 2& 2\end{array}\right]=\left[\begin{array}{ccc}1& 0& 0\\ \frac{3}{2}& 1& 0\\ -\frac{1}{2}& 0& 1\end{array}\right]\times [\left[\begin{array}{ccc}2& -4& 0\\ 0& 5& 4\\ 0& 0& 2\end{array}\right],\text{b=}\left[\begin{array}{l}2\\ 0\\ -5\end{array}\right]$