Odpowiedź:
[tex]a)\\\\\begin{cases}\frac{4y-3x}{18}-\frac{y+4}{6}=\frac{y}{9}\ \ /*18\\\frac{y-x}{2}=8y+4x\ \ /*2\end{cases}\\\\\\\begin{cases}4y-3x-3(y+4)=2y\\y-x=16y+8x\end{cases}\\\\\\\begin{cases}4y-3x-3y-12=2y\\y-x-16y-8x=0\end{cases}\\\\\\\begin{cases}y-3x-2y=12\\-9x-15y=0\ \ /:3\end{cases}\\\\\\\begin{cases}-3x-y=12\ \ /*(-1)\\-3x-5y=0\end{cases}\\\\\\\begin{cases}3x+y=-12\\-3x-5y=0\end{cases}\\\\\\\begin{cases}y=-12-3x\\-3x-5y=0\end{cases}[/tex]
[tex]-3x-5(-12-3x)=0\\\\-3x+60+15x=0\\\\12x=-60\ \ /:12\\\\x=-5\\\\\\y=-12-3*(-5)=-12+15=3\\\\\\\begin{cases}x=-5\\y=3\end{cases}[/tex]
[tex]b)\\\\\begin{cases}(y-2)^2-2(y-2x)=1-(3-y)(3+y)\\2y+x=4\end{cases}\\\\\\\begin{cases}y^2-4y+4-2y+4x=1-(9-y^2)\\x+2y=4\end{cases}\\\\\\\begin{cases}y^2-6y+4+4x=1-9+y^2\\x+2y=4\end{cases}\\\\\\\begin{cases}y^2-6y+4x-y^2=-8-4\\x+2y=4\end{cases}\\\\\\\begin{cases}4x-6y=-12\ \ /:2\\x+2y=4\end{cases}\\\\\\\begin{cases}2x-3y=-6\\x=4-2y\end{cases}[/tex]
[tex]2(4-2y)-3y=-6\\\\8-4y-3y=-6\\\\-7y=-6-8\\\\-7y=-14\ \ /:(-7)\\\\y=2\\\\\\x=4-2*2=4-4=0\\\\\\\begin{cases}x=0\\y=2\end{cases}[/tex]
