3. The chord $A B$ of the parabola $y=x^{2}$ intersects the y-axis at point $C$ and is divided by it in the ratio $A C: C B=5: 2$. Find the abscissas of points $A$ and $B$, if the ordinate of point $C$ is 20.
Answer: $\left(x_{A}=-5 \sqrt{2}, x_{B}=2 \sqrt{2}\right),\left(x_{A}=5 \sqrt{2}, x_{B}=-2 \sqrt{2}\right)$.