Given A=[884221]\displaystyle {A}={\left[\begin{array}{cc} -{8}&-{84}\\-{2}&-{21}\end{array}\right]} , find A1\displaystyle {A}^{{-{1}}} . If A1\displaystyle {A}^{{-{1}}} does not exist, write "DNE" in each box.

   

   

Hint 1