# How do you combine and simplify sqrt(25/128)?

$\frac{\sqrt{25}}{\sqrt{128}} = \frac{5}{\sqrt{64} \sqrt{2}} = \frac{5}{8 \sqrt{2}}$
You should multiply top and bottom by $\sqrt{2}$ to rationalise the fraction.
$\frac{5}{8 \sqrt{2}} \times \frac{\sqrt{2}}{\sqrt{2}}$
$\frac{5 \sqrt{2}}{8 \sqrt{4}} = \frac{5 \sqrt{2}}{16}$