$\displaystyle

\sqrt{x+a} + \sqrt{x - a} = \sqrt{2} \sqrt{x+7}

$

i need it simplified (it is multiple choice) but as much as i may try i cant rember how to do this type of problem plz help thank you.

if u want the 5 choices i have..i can give them...but it owuld do no good because i still want to know how to solve the problem (show the work if you can)