\[C(x;y):\]
\[x = \frac{- 5 + 6}{2} = \frac{1}{2} = 0,5;\]
\[y = \frac{1 + 9}{2} = \frac{10}{2} = 5.\]
\[C(0,5;\ 5).\]
\[Ответ:C(0,5;5).\]