Respuesta :

25x²-4y²=400

(x-h)²/a²-(y-k)²/b²=1

(5x)²-(2y)²=400

(x)²/16 - (y)²/100 = 1

a²+b²=c²

16+100=c²

c²=116

c=-+√116

foci are (-√116,0) and (√116,0)