Answer
$\left[\begin{array}{rrr}
\dfrac{3}{2} & 0 & -\dfrac{1}{2}\\\\
\dfrac{5}{2} & -\dfrac{1}{2} & \dfrac{1}{2}
\end{array}\right]$
Work Step by Step
$A=\left[\begin{array}{lll}
1 & -1 & 0\\
0 & 2 & 1
\end{array}\right],\quad B=\left[\begin{array}{lll}
3 & 0 & -1\\
5 & -1 & 1
\end{array}\right],\quad C=\left[\begin{array}{lll}
x & 1 & w\\
z & r & 4
\end{array}\right]$
$(\displaystyle \frac{1}{2}B)_{ij}=\frac{1}{2}\cdot b_{ij}$
---
$\displaystyle \frac{1}{2}\cdot B=\left[\begin{array}{lll}
\frac{1}{2}\cdot 3 & \frac{1}{2}\cdot 0 & \frac{1}{2}\cdot(-1)\\
\frac{1}{2}\cdot 5 & \frac{1}{2}\cdot(-1) & \frac{1}{2}\cdot 1
\end{array}\right]=\displaystyle \left[\begin{array}{lll}
\frac{3}{2} & 0 & -\frac{1}{2}\\
\frac{5}{2} & -\frac{1}{2} & \frac{1}{2}
\end{array}\right]$