Sam L.

Two matrices are ________ if all of their corresponding entries are equal.

A matrix consisting entirely of zeros is called a ________ matrix and is denoted by ________.

In Exercises 7-10, find $x$ and $y$.

$\left[ \begin{array}{r} x & -2 \\ 7 & y \end{array} \right] = \left[ \begin{array}{r} -4 & -2 \\ 7 & 22 \end{array} \right]$

In Exercises 7-10, find $x$ and $y$.

$\left[ \begin{array}{r} 16 & 4 & 5 & 4 \\ -3 & 13 & 15 & 6 \\ 0 & 2 & 4 & 0 \end{array} \right] = \left[ \begin{array}{r} 16 & 4 & 2x+1 & 4 \\ -3 & 13 & 15 & 3x \\ 0 & 2 & 3y-5 & 0 \end{array} \right]$

In Exercises 11-18, if possible, find (a) $A+B$, (b) $A-B$, (c ) $3A$, and (d) $3A-2B$.

$A = \left[ \begin{array}{r} 1 & -1 \\ 2 & -1 \end{array} \right]$, $B = \left[ \begin{array}{r} 2 & -1 \\ -1 & 8 \end{array} \right]$

In Exercises 11-18, if possible, find (a) $A+B$, (b) $A-B$, (c ) $3A$, and (d) $3A-2B$.

$A = \left[ \begin{array}{r} 1 & 2 \\ 2 & 1 \end{array} \right]$, $B = \left[ \begin{array}{r} -3 & -2 \\ 4 & 2 \end{array} \right]$