JEE Previous Year Question

If the co-ordinate of two points $A$ and $B$ are $\left(\sqrt{7}\text{,}0\right)$ and $(-\sqrt{7}\text{,}0)$ respectively and $P$ is any point on the conic, $9x^2+16y^2=144$, then $\text{PA}+\text{PB}$ is equal to:

Topic: JEE PYQ

Answer: D. Full step-by-step solution below.