Answer
Foci:
$(-\sqrt{13},0)$ and $(\sqrt{13},0)$.
Work Step by Step
Major axis parallel to the x-axis, horizontal
$a^{2}=49$
$a=7$
$b^{2}=36,$
$b=6$
Center: (0,0)
Vertices: $(h-a, k),\quad (h+a, k) $
$(-7, 0),\quad (7, 0) $
Foci are $c$ units right and $c$ units left of center,
where $c^{2}=a^{2}-b^{2}:$
$c^{2}=a^{2}-b^{2}=49-36=13$
$c=\sqrt{13}$
Foci:
$(-\sqrt{13},0)$ and $(\sqrt{13},0)$.
