If the distance from a point P on the hyperbola x2 / 25-y2 / 9 = 1 to one focus is 15, then the distance from it to another focus is 15

If the distance from a point P on the hyperbola x2 / 25-y2 / 9 = 1 to one focus is 15, then the distance from it to another focus is 15

|Pf1-15 | = 10 Pf1 = 15 ± 10 Pf1 = 5 or Pf1 = 15