\[y = 2x^{2} + x\ и\ y = - 2x + 20\]
\[2x^{2} + x = - 2x + 20\]
\[2x^{2} + x + 2x - 20 = 0\]
\[2x^{2} + 3x - 20 = 0\]
\[D = 9 + 160 = 169\]
\[x_{1} = \frac{- 3 + 13}{4} = \frac{10}{4} = 2,5;\]
\[x_{2} = \frac{- 3 - 13}{4} = - \frac{16}{4} = - 4.\]
\[y_{1} = - 2 \cdot 2,5 + 20 = 15;\]
\[y_{2} = - 2 \cdot ( - 4) + 20 = 28.\]
\[Координаты\ точек\ пересечения\ графиков:\]
\[(2,5;15);\ \ ( - 4;28).\]