Given $A,b,L$ and $U,$ find $x$ using an $LU$ Decomposition. Show all steps for full credit.

$A=\left[\begin{array}{ccc}4& 3& 3\end{array}\right]$

$6$

$b=\left[\begin{array}{c}1\end{array}\right]$

$1$

$L=\left[\begin{array}{ccc}1& 0& ?\end{array}\right]$

$1\mathrm{.}51$

$U=\left[\begin{array}{ccc}4& 3& ?\end{array}\right]$

$0-1\mathrm{.}5$