Odpowiedź:
[tex]a)\\\\\begin{cases}3x-2y=10\ \ /\cdot3\\2x+3y=-2\ \ /\cdot2\end{cases}\\\\\\+\begin{cases}9x-6y=30\\4x+6y=-4\end{cases}\\---------\\13x=26\ \ /:13\\x=2\\\\\\2\cdot2+3y=-2\\\\4+3y=-2\\\\3y=-2-4\\\\3y=-6\ \ /:3\\\\y=-2\\\\\begin{cases}x=2\\y=-2\end{cases}[/tex]
[tex]b)\\\\\begin{cases}4x+7y=7\ \ /\cdot3\\3x+6y=3\ \ /\cdot(-4)\end{cases}\\\\\\+\begin{cases}12x+21y=21\\-12x-24y=-12\end{cases}\\-----------\\-3y=9\ \ /:(-3)\\y=-3\\\\\\3x+6\cdot(-3)=3\\\\3x-18=3\\\\3x=3+18\\\\3x=21\ \ /:3\\\\x=7\\\\\begin{cases}x=7\\y=-3\end{cases}[/tex]
[tex]c)\\\\\begin{cases}6x+2y=13\ \ /\cdot7\\4x-7y=2\ \ /\cdot2\end{cases}\\\\\\+\begin{cases}42x+14y=91\\8x-14y=4\end{cases}\\---------\\50x=95\ \ /:50\\\\x=\frac{95}{50}\\\\x=\frac{19}{10}\\\\x=1\frac{9}{10}\\\\\\\not6^3\cdot\frac{19}{\not10_{5}}+2y=13\\\\\frac{57}{5}+2y=13\\\\2y=13-\frac{57}{5}\\\\2y=\frac{65}{5}-\frac{57}{5}\\\\2y=\frac{8}{5}\ \ /:2\\\\y=\frac{\not8^4}{5}\cdot\frac{1}{\not2_{1}}\\\\y=\frac{4}{5}\\\\\begin{cases}x=1\frac{9}{10}\\y=\frac{4}{5}\end{cases}[/tex]
