$\displaystyle \sqrt{35x}/\sqrt{7x}$
It's not a multiplication problem ... Basically, MathStud put the two square roots into one:
$\displaystyle \frac{\sqrt{35x}}{\sqrt{7x}} = \sqrt{\frac{35x}{7x}} = \text{Etc.}$
since as he said:
$\displaystyle \frac{a^{c}}{b^{c}} = \left(\frac{a}{b}\right)^{c}$
where $\displaystyle c = \frac{1}{2}$ here