Can someone please tell me how to answer this question please and thank you

12. A satellite of mass 20.0 kg is in an elliptical orbit around the Earth. At perigee (the point nearest the Earth) the satellite is located a distance of 8.00 x 10 m from the Earth's center, travelling at 8.26 x 10' m/s. Conversely, at apogee (the point furthest from Earth) the satellite is travelling with a speed of 4.29 x 10* m/s. How far away from the Earth's center is the satellite at apogee