Answer:
[tex]\huge\boxed{A-B=\left[\begin{array}{ccc}-11&1&-15\\-7&8&8\\0&-7&1\end{array}\right] }[/tex]
Step-by-step explanation:
[tex]A-B=\left[\begin{array}{ccc}-2&-8&-9\\-5&7&5\\-4&-8&7\end{array}\right] -\left[\begin{array}{ccc}9&-9&6\\2&-1&-3\\-4&-1&6\end{array}\right] \\\\=\left[\begin{array}{ccc}-2-9&-8-(-9)&-9-6\\-5-2&7-(-1)&5-(-3)\\-4-(-4)&-8-(-1)&7-6\end{array}\right] \\\\=\left[\begin{array}{ccc}-11&1&-15\\-7&8&8\\0&-7&1\end{array}\right][/tex]
