\[y = 3x^{2} + 2x\]
\[Пересечение\ с\ осью\ абсцисс\ (y = 0):\]
\[3x^{2} + 2x = 0\]
\[x(3x + 2) = 0\]
\[x = 0;\ \ \ x = - \frac{2}{3}\]
\[A(0;0);\ \ B\left( - \frac{2}{3};0 \right).\]