To solve the system
$\begin{bmatrix} -1 & 1 & 2 \\ -2 & 3 & 5 \\ -3 & 6 & 10 \end{bmatrix} x = \begin{bmatrix} 11 \\ 29 \\ 57 \end{bmatrix}$
using the LU factorization, you would first solve
$Ly = \begin{bmatrix} 11 \\ \\ \end{bmatrix}$
and then solve
$Ux = \begin{bmatrix} 11 \\ 7 \\ 8 \end{bmatrix}$
Find the solution $x = \begin{bmatrix} 4 \\ -1 \\ 8 \end{bmatrix}$
