\begin{equation}4x+9y=5\textrm{ },\textrm{ }(-4)x+9y=3\end{equation}

\begin{equation}x+4y=5\textrm{ },\textrm{ }-x+7y=-8\end{equation}

\begin{equation}9x-5y=-9\textrm{ },\textrm{ }6x+5y=10\end{equation}

\begin{equation}\frac{1}{7} \times x-\frac{6}{7} \times y=-(\frac{10}{7})\textrm{ },\textrm{ }(-(\frac{1}{7})) \times x+6y=8\end{equation}

\begin{equation}5x-6y=-3\textrm{ },\textrm{ }3x+6y=8\end{equation}

\begin{equation}x+5y=-3\textrm{ },\textrm{ }-x+10y=-10\end{equation}

\begin{equation}3x+y=-6\textrm{ },\textrm{ }8x-y=-8\end{equation}

\begin{equation}10x+4y=6\textrm{ },\textrm{ }10x+9y=4\end{equation}

\begin{equation}(-27)x+10y=8\textrm{ },\textrm{ }3x+4y=8\end{equation}

\begin{equation}8x+9y=7\textrm{ },\textrm{ }9x+6y=7\end{equation}

\begin{equation}9x+y=10\textrm{ },\textrm{ }(-10)x+y=-2\end{equation}

\begin{equation}2x-5y=-8\textrm{ },\textrm{ }4x=10+5y\end{equation}

\begin{equation}x-6y=4\textrm{ },\textrm{ }(-2)x=6y+5\end{equation}

\begin{equation}(-3)x+9y=8\textrm{ },\textrm{ }9x-y=-4\end{equation}

\begin{equation}y-2x=9\textrm{ },\textrm{ }6y-x=10\end{equation}

\begin{equation}(-4)x+y=0\textrm{ },\textrm{ }3x+7y=-2\end{equation}