## College Algebra (6th Edition)

$\frac{x^2}{16}+\frac{y^2}{25}=1$
If we divide the equation by $400$, we obtain: $25x^2+16y^2=400\\ \frac{25x^2}{400}+\frac{16y^2}{400}=\frac{400}{400}\\ \frac{x^2}{16}+\frac{y^2}{25}=1$