College Algebra, Chapter 7, 7.2, Section 7.2, Problem 8

Evaluate $\left[ \begin{array}{ccc} 0 & 1 & 1 \\ 1 & 1 & 0 \end{array} \right] - \left[ \begin{array}{ccc} 2 & 1 & -1 \\ 1 & 3 & -2 \end{array} \right]$ or explain why it can not be performed.


$\begin{equation} \begin{aligned} \left[ \begin{array}{ccc} 0 & 1 & 1 \\ 1 & 1 & 0 \end{array} \right] - \left[ \begin{array}{ccc} 2 & 1 & -1 \\ 1 & 3 & -2 \end{array} \right] =& \left[ \begin{array}{ccc} 0-2 & 1-1 & 1-(-1) \\ 1-1 & 1-3 & 0-(-2) \end{array} \right] \\ \\ \\ \\ =& \left[ \begin{array}{ccc} -2 & 0 & 2 \\ 0 & -2 & 2 \end{array} \right] \end{aligned} \end{equation}$