Originally Posted by

**Splint** Please be understanding if this is a stupid question as I am making a comeback to algebra after 20 years of not using it.

The following appears in my text book...

$\displaystyle \frac{x}{3\sqrt(100^2+x^2)}=\frac{1}{5}$

the next line is....

$\displaystyle 5x=3\sqrt(100^2+x^2)$

it is the $\displaystyle 5x$ which bothers me, I would have thought to multiply both sides by $\displaystyle 3\sqrt(100^2+x^2)$ then divide both sides by $\displaystyle \frac{1}{5}$ which would in my mind result in $\displaystyle \frac{x}{5}=3\sqrt(100^2+x^2)$

Have I missed the point here?

Splint