When the price of a certain commodity is $\displaystyle {p}$ dollars per unit, the manufacturer is willing to supply $\displaystyle {x}$  thousand units, where:

$\displaystyle {x}^{{2}}-{x}\sqrt{{{p}}}-{p}^{{2}}={85}$

If the price is $\displaystyle \${14}$  per unit and is increasing at the rate of $\displaystyle {59}$ cents per week, the supply is changing by units per week.