Chapter 11 - Section 11.2 - Ellipses - 11.2 Exercises - Page 797: 8

III

Let's rewrite this. When we do so and divide both sides by 400 we get $x^2/25+y^2/16=1$ So we notice immediately that the major axis will be on the x-axis since the number under $x^2$ is more than that of $y^2$. Also since the intercepts will be the square roots of the numbers under the bar, the x intercept are +5,-5 and the y intercepts are +4,-4. These qualities match graph 3.