Giải thích các bước giải:
\(\begin{array}{l}
a,\left\{ \begin{array}{l}
\frac{x}{{ - 2}} = \frac{y}{3}\\
\frac{x}{{ - 2}} = 1\\
\frac{z}{5} = 1
\end{array} \right. \to \left\{ \begin{array}{l}
x = - 2\\
z = 5\\
y = 3
\end{array} \right.\\
b,\left\{ \begin{array}{l}
\frac{{ - x}}{{12}} = 2\\
\frac{{ - x}}{{12}} = \frac{y}{6}\\
\frac{z}{3} = 2
\end{array} \right. \to \left\{ \begin{array}{l}
x = - 24\\
z = 6\\
y = 12
\end{array} \right.\\
c,\left\{ \begin{array}{l}
\frac{x}{2} = \frac{1}{2}\\
\frac{3}{{ - y}} = \frac{1}{2}\left( {y \ne 0} \right)\\
\frac{z}{4} = \frac{1}{2}\\
\frac{t}{{18}} = \frac{1}{2}
\end{array} \right. \to \left\{ \begin{array}{l}
x = 1\\
y = - 6\\
z = 2\\
t = 9
\end{array} \right.
\end{array}\)
