Answer
$25,64$
Work Step by Step
Step 1. Rewrite the equation as $x+40=13\sqrt x$
Step 2. Take square on both sides to get $x^2+80x+1600=169x$ or $x^2-89x+1600=0$
Step 3. Factor the equation to get $(x-25)(x-64)=0$, thus $x=25$ and $x=64$
Step 4. Check the answers with the original equation, we find they both fit.