so hmm if you notice the picture below
between 2 and 16, there are 14 units, so, the center is half-way in between, thus, is at y = 7, or -2, 7
because, the major axis is over the y-axis, then the "a" component, goes under the fraction with the "y" in the numerator
[tex]\bf \textit{ellipse, vertical major axis}\\\\
\cfrac{(x-{{ h}})^2}{{{ b}}^2}+\cfrac{(y-{{ k}})^2}{{{ a}}^2}=1
\qquad center\ ({{ h}},{{ k}})\qquad
vertices\ ({{ h}}, {{ k}}\pm a)\\\\
-----------------------------\\\\
\begin{cases}
b=4\\
a=7\\
h=-2\\
k=7
\end{cases}\implies \cfrac{(x+2)^2}{4^2}+\cfrac{(y-7)^2}{7^2}\implies \cfrac{(x+2)^2}{16}+\cfrac{(y-7)^2}{49}[/tex]
