Given that the hyperbola and the square of ellipse X / 9 + the square of ellipse Y / 25 = 1 are in common focus, the sum of their eccentricities is 7 / 5, the hyperbolic equation is solved I'm sorry, but the difference between their eccentricities is 7 / 5

Given that the hyperbola and the square of ellipse X / 9 + the square of ellipse Y / 25 = 1 are in common focus, the sum of their eccentricities is 7 / 5, the hyperbolic equation is solved I'm sorry, but the difference between their eccentricities is 7 / 5

Then the focus is (- 4,0) (4,0) the eccentricity of the ellipse is C / a = 4 / 5, then you can know that the hyperbolic eccentricity is 7 / 5-4 / 5 = 3 / 5 = C / A, known C = 4, substituted by 3 / 5 = C / A, a = ~ it seems that there is something wrong with your topic, because the eccentricity of the hyperbola should be greater than 1 ~ then you should follow my above process