Answer
a. $\left[\begin{array}{ll}
3 & 2\\
6 & 2\\
5 & 7
\end{array}\right]$
b. $\left[\begin{array}{ll}
-1 & 4\\
0 & 6\\
5 & 5
\end{array}\right]$
c. $\left[\begin{array}{ll}
-4 & -12\\
-12 & -16\\
-20 & -24
\end{array}\right]$
d. $\left[\begin{array}{ll}
7 & 7\\
15 & 8\\
15 & 20
\end{array}\right]$
Work Step by Step
a.
$A+B=\left[\begin{array}{ll}
1+2 & 3-1\\
3+3 & 4-2\\
5+0 & 6+1
\end{array}\right]=\left[\begin{array}{ll}
3 & 2\\
6 & 2\\
5 & 7
\end{array}\right]$
b.
$A-B=\left[\begin{array}{ll}
1-2 & 3-(-1)\\
3-3 & 4-(-2)\\
5-0 & 6-1
\end{array}\right]=\left[\begin{array}{ll}
-1 & 4\\
0 & 6\\
5 & 5
\end{array}\right]$
c.
$-4A=\left[\begin{array}{ll}
-4(1) & -4(3)\\
-4(3) & -4(4)\\
-4(5) & -4(6)
\end{array}\right]=\left[\begin{array}{ll}
-4 & -12\\
-12 & -16\\
-20 & -24
\end{array}\right]$
d.
$3A+2B=\left[\begin{array}{ll}
3(1)+2(2) & 3(3)+2(-1)\\
3(3)+2(3) & 3(4)+2(-2)\\
3(5)+2(0) & 3(6)+2(1)
\end{array}\right]=\left[\begin{array}{ll}
7 & 7\\
15 & 8\\
15 & 20
\end{array}\right]$