Find , if . Using , solve the system of linear equations: , ,

Find $A^{-1}$, if $A = \begin{pmatrix} 1 & 2 & 0 \\\\ -2 & -1 & -2 \\\\ 0 & -1 & 1 \end{pmatrix}$. Using $A^{-1}$, solve the system of linear equations: $x - 2y = 10$, $2x - y - z = 8$, $-2y + z = 7$