algebra 2 help?

Question

Find the eccentricity of the following:
x^2/16 + y^2/25 = 1

A SQRT(3/5)
B 3/4
C 4/5
D 3/5
E 5/3
F SQRT(4/5)

Answer 1

if you think of "a" as the semi-major length, here it's 5. e = c/a, and c² = a²-b² = 25-16 = 9, so c = 3. that makes eccentricity 3/5, D.

Answer 2

Since y^2 has a larger divisor than x^2, the semi-major axis is parallel to the y-axis. The eccentricity is sqrt(1 - 16/25) = sqrt(9/25) = 3/5, choice D.

Answer 3

Work out your own homework or you are cheating yourself........