It is given that b = 3, c=4, centre at the origin; foci on the x axis.

Since the foci are on the x-axis, the major axis is along the x-axis.

Therefore, the equation of the ellipse will be of the form =1, where a is the semi-major axis.

Accordingly, b = 3 and c=4.

It is known that a² = b²+c².

a² = 3²+4² = 9+16 =25

a =5

Thus, the equation of the ellipse is or = 1.