Odpowiedź:
[tex]Zad.3\\\\\begin{cases}3x-4y=1\ \ /\cdot(-2)\\6x+3y=13\end{cases}\\\\\\+\begin{cases}-6x+8y=-2\\6x+3y=13\end{cases}\\---------\\11y=11\ \ /:11\\y=1\\\\\\3x-4\cdot1=1\\\\3x-4=1\\\\3x=1+4\\\\3x=5\ \ /:3\\\\x=\frac{5}{3}\\\\\\\begin{cases}x=\frac{5}{3}\\y=1\end{cases}[/tex]
[tex]Zad.4\\\\\begin{cases}3x-1=y\\2x-4y=-6\end{cases}\\\\\\2x-4(3x-1)=-6\\\\2x-12x+4=-6\\\\-10x+4=-6\\\\-10x=-6-4\\\\-10x=-10\ \ /:(-10)\\\\x=1\\\\\\3\cdot1-1=y\\\\3-1=y\\\\2=y\\\\y=2\\\\\\\begin{cases}x=1\\y=2\end{cases}[/tex]
