## Precalculus (10th Edition)

the major axis is the x-axis, $a=5$, $b=3$
The equation of the ellipse here has the form $\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$, where $a\gt b\gt0$, hence the major axis is the x-axis, $a^2=25\\a=\sqrt{25}=5$, $b^2=9\\b=\sqrt{9}=3$