\begin{equation}4x+4y=5\textrm{ },\textrm{ }(-4)x+9y=7\end{equation}

\begin{equation}x+9y=3\textrm{ },\textrm{ }-x+4y=-6\end{equation}

\begin{equation}7x-8y=-4\textrm{ },\textrm{ }7x+8y=2\end{equation}

\begin{equation}\frac{1}{8} \times x-\frac{10}{8} \times y=-(\frac{10}{8})\textrm{ },\textrm{ }(-(\frac{1}{8})) \times x+10y=9\end{equation}

\begin{equation}6x-6y=-9\textrm{ },\textrm{ }10x+6y=8\end{equation}

\begin{equation}x+4y=-7\textrm{ },\textrm{ }-x+9y=-8\end{equation}

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

\begin{equation}9x+7y=7\textrm{ },\textrm{ }9x+5y=2\end{equation}

\begin{equation}(-70)x+6y=10\textrm{ },\textrm{ }7x+5y=5\end{equation}

\begin{equation}6x+2y=4\textrm{ },\textrm{ }3x+3y=7\end{equation}

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

\begin{equation}7x-3y=-8\textrm{ },\textrm{ }7x=8+3y\end{equation}

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

\begin{equation}(-6)x+10y=3\textrm{ },\textrm{ }36x-y=-9\end{equation}

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

\begin{equation}(-3)x+y=0\textrm{ },\textrm{ }6x+10y=-10\end{equation}