Question 30249
This one is solved by simple observation.
x²+y²=16 is the eqn of a circle, centre the origin, with a radius of r = 4.
x²/5² + y²/4² = 1 is the eqn of an ellipse, centre the origin, with semi-major axis,a = 5 and semi-minor axis, b = 4.

{{{ graph( 300, 200, -6, 6, -5, 5, sqrt(16 - x^2), -sqrt(16 - x^2),4*sqrt(1-x^2/25), -4*sqrt(1-x^2/25)) }}}

As you can see there are only two points of intersection (when both functions have a common point with the same x- and y-coordinates)
The points of intersection are:
(0,4) and (0,-4)
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