Solve for $\displaystyle {x}$ and $\displaystyle {y}$ in the matrix $\displaystyle {A}={\left[\begin{array}{cc} {x}&-{2}\\-{4}&{y}\end{array}\right]}$

if $\displaystyle {A}^{{2}}={\left[\begin{array}{cc} {89}&{24}\\{48}&{17}\end{array}\right]}$.

$\displaystyle {x}=$

$\displaystyle {y}=$