Answer
$a) -4p-4+0$
$b) -44$
The increase in demand is at the rate of $44$ items for each increase of one dollar.
Work Step by Step
$a) D(p) = -2p^2-4p+300$
The rate of change can be ascertained by differentiating the function with respect to $p$.
$\implies D'(p) = -4p-4+0=-4p-4$
This is the rate of change of demand with respect to price.
$b) D'(10) = -4(10)-4 = -44$
