問題文全文(内容文)：
(　)も分数も少数も全部消してやるぜ！
①
$\begin{eqnarray}
\left\{
\begin{array}{l}
3(x+y)=4x-7 \\
2x=3y+8
\end{array}
\right.
\end{eqnarray}$
②
$\begin{eqnarray}
\left\{
\begin{array}{l}
0.5x-0.2y=2 \\
2x-3y=-3
\end{array}
\right.
\end{eqnarray}$
③
$\begin{eqnarray}
\left\{
\begin{array}{l}
\displaystyle \frac{x}{3}=+\displaystyle \frac{y}{4}=-1 \\
3y=5x-9
\end{array}
\right.
\end{eqnarray}$
④
$\begin{eqnarray}
\left\{
\begin{array}{l}
2(3x+y)=8x+y+9 \\
5x-4y+30=0
\end{array}
\right.
\end{eqnarray}$

問題文全文(内容文)：
$\begin{eqnarray}
\left\{
\begin{array}{l}
5x+2y=-9 \\
-2x+9y=-16
\end{array}
\right.
\end{eqnarray}$

問題文全文(内容文)：
中2~連立方程式(加減法)~

例題次の連立方程式を解きなさい。

(1)
$\begin{eqnarray}
\left\{
\begin{array}{l}
4x-3y=11 \\
2x-3y=7
\end{array}
\right.
\end{eqnarray}$

(2)
$\begin{eqnarray}
\left\{
\begin{array}{l}
2x-5y=7 \\
-2x+3y=-1
\end{array}
\right.
\end{eqnarray}$

(3)
$\begin{eqnarray}
\left\{
\begin{array}{l}
2x+3y-16 \\
3x-4y=7
\end{array}
\right.
\end{eqnarray}$

(4)
$\begin{eqnarray}
\left\{
\begin{array}{l}
5x-6y=-8 \\
9x-4y=6
\end{array}
\right.
\end{eqnarray}$

問題文全文(内容文)：
$
\begin{eqnarray}
\left\{
\begin{array}{l}
51x + 49y = 1 \\
49x + 51y = 2
\end{array}
\right.
\end{eqnarray}
$
慶應義塾高等学校

問題文全文(内容文)：
①
$\begin{eqnarray}
\left\{
\begin{array}{l}
3x-2y=7 \\
x=y+4
\end{array}
\right.
\end{eqnarray}$


②
$\begin{eqnarray}
\left\{
\begin{array}{l}
2x+3y=13 \\
y=2x-1
\end{array}
\right.
\end{eqnarray}$