Odpowiedź:
[tex]d)\\\\\begin{cases}5x-2y=16\ \ /\cdot5\\3x+5y=-9\ \ /\cdot2\end{cases}\\\\\\+\begin{cases}25x-10y=80\\6x+10y=-18\end{cases}\\----------\\31x=62\ \ /:31\\x=2\\\\\\3\cdot2+5y=-9\\\\6+5y=-9\\\\5y=-9-6\\\\5y=-15\ \ /:5\\\\y=-3\\\\\\\begin{cases}x=2\\y=-3\end{cases}[/tex]
[tex]e)\\\\\begin{cases}10x+21y=-9\\-5x-7y=8\ \ /\cdot3\end{cases}\\\\\\+\begin{cases}10x+21y=-9\\-15x-21y=24\end{cases}\\----------\\-5x=15\ \ /:(-5)\\x=-3\\\\\\-5\cdot(-3)-7y=8\\\\15-7y=8\\\\-7y=8-15\\\\-7y=-7\ \ /:(-7)\\\\y=1\\\\\\\begin{cases}x=-3\\y=1\end{cases}[/tex]
[tex]f)\\\\\begin{cases}2x+3y=-3,5\ \ /\cdot2\\3x-2y=4,5\ \ /\cdot3\end{cases}\\\\\\+\begin{cases}4x+6y=-7\\9x-6y=13,5\end{cases}\\---------\\13x=6,5\ \ /:13\\\\x=0,5\\\\\\2\cdot0,5+3y=-3,5\\\\1+3y=-3,5\\\\3y=-3,5-1\\\\3y=-4,5\ \ /:3\\\\y=-1,5\\\\\\\begin{cases}x=0,5\\y=-1,5\end{cases}[/tex]
