What is the shortest distance between the lines [math]x-\frac{2}{3}=y-\frac{3}{4}=z-\frac{1}{4}[/math] and [math]x-\frac{1}{2}=y-\frac{2}{3}=z-\frac{3}{4}[/math]? 
How do you solve for [math]x[/math] in [math]\frac{z^4y^2}3=\frac{\sqrt{px}\,b^3}{y^4}[/math]?