The demand equation for a smartphone is

$p=5000(1-\frac{3}{3+e^{-0\mathrm{.}001x}}).$

Find the demand $x$ for each price. $($Round your answers to the nearest whole number.$)$

$($a$)D=$$$184$

$x=$

units

$($b$),D=$$$284$

$x=$

$x$ units