Clearly, the foci (±4, 0) lie on x-axis.
∴ The equation of ellipse in standard form is

x2

a2

+

y2

b2

= 1
Now vertices are (±5, 0) ⇒ a = 5, foci are (±4, 0) ⇒ c = 4
Also, we know that c2 = a2–b2
∴ (4)2 = (5)2–b2 ⇒ b2 = 25 – 16 = 9.
Hence the required equation of ellipse is

x2

25

+

y2

9

= 1