If $x_1, y_1$ are the roots of $x^2 + 8x - 20 = 0$, $x_2, y_2$ are the roots of $4x^2 + 32x - 57 = 0$ and $x_3, y_3$ are the roots of $9x^2 + 72x - 112 = 0$, then the points $(x_1, y_1)$, $(x_2, y_2)$ and $(x_3, y_3)$ -