Answer
$\left[\begin{array}{rr}
0.25 & -2\\
1 & 0.5\\
0 & 5
\end{array}\right]$
Work Step by Step
$A=\left[\begin{array}{ll}
0 & -1\\
\mathrm{l} & 0\\
-1 & 2
\end{array}\right], \quad B=\left[\begin{array}{ll}
0.25 & -\mathrm{l}\\
0 & 0.5\\
-\mathrm{l} & 3
\end{array}\right],\quad C=\left[\begin{array}{ll}
\mathrm{l} & -1\\
1 & 1\\
-1 & -1
\end{array}\right]$.
$(A+B)_{ij}=A_{ij}+B_{ij}$
$A+B=\left[\begin{array}{rr}
0+0.25 & -1+(-1)\\
\mathrm{l}+0 & 0+0.5\\
-1+(-1) & 2+3
\end{array}\right]=\left[\begin{array}{ll}
0.25 & -2\\
1 & 0.5\\
0 & 5
\end{array}\right]$
