Solve the following systems using Partial Pivoting and pointers:
(a)
$$
\begin{aligned}
& \text { (a) }\left(\begin{array}{rr}
1 & 5 \\
2 & -3
\end{array}\right)\left(\begin{array}{l}
x \\
y
\end{array}\right)=\left(\begin{array}{r}
3 \\
-2
\end{array}\right), \quad \text { (b) }\left(\begin{array}{rrr}
1 & 2 & -1 \\
4 & -2 & 1 \\
3 & 5 & -1
\end{array}\right)\left(\begin{array}{l}
x \\
y \\
z
\end{array}\right)=\left(\begin{array}{l}
1 \\
3 \\
1
\end{array}\right), \\
& \text { (c) }\left(\begin{array}{rrrr}
1 & -3 & 6 & -1 \\
2 & -5 & 0 & 1 \\
-1 & -6 & 4 & -2 \\
3 & 0 & 2 & -1
\end{array}\right)\left(\begin{array}{l}
x \\
y \\
z \\
w
\end{array}\right)=\left(\begin{array}{r}
1 \\
-2 \\
0 \\
1
\end{array}\right), \quad(d)\left(\begin{array}{rrr}
01 & 4 & 2 \\
2 & -802 & 3 \\
7 & .03 & 250
\end{array}\right)\left(\begin{array}{l}
x \\
y \\
z
\end{array}\right)=\left(\begin{array}{r}
1 \\
2 \\
122
\end{array}\right) .
\end{aligned}
$$