Odpowiedź:
[tex]\begin{cases}2x+3y=1\\x+2y=7\end{cases}\\\\\\\begin{cases}2x+3y=1\\x=7-2y\end{cases}\\\\\\2(7-2y)+3y=1\\\\14-4y+3y=1\\\\-y=1-14\\\\-y=-13\ \ /*(-1)\\\\y=13\\\\\\x=7-2*13=7-26=-19\\\\\\\begin{cases}x=-19\\y=13\end{cases}[/tex]
