[tex]ilosc\ osob\ :\ \ 750 \\ilosx\ dzieci:\ x\\ilosc\ doroslych: \ y\\ilosc\ talerzy:\ \ 2994\\\\\begin{cases}x+y=750\ \ *(-2)\\2x+5y=2994 \end{cases}\\\\\begin{cases}-2x-2y=-1500\\2x+5y=2994 \end{cases}\\+---------\\3y=1494\ \ :3\\ y=498\\\\x+y=750\\x=750-y\\[/tex]
[tex]x+y=750\\x=750-y\\ x=750-498\\x=252\\\\\begin{cases}x=252\\y=498 \end{cases}\\\\odp. \ Na\ tej\ imprezie\ bedzie\ 498\ osob\ doroslych\ i\ 252\ dzieci.[/tex]
