$8.$The price$-$demand and cost functions for the production and sales of $x$ Mini$-$Vacs are given as

$p(x)=25-\mathrm{.}25x$

$C(x)=250+5x$

The price per Mini$-$Vac $p(x)$ and the cost $C(x)$ are in dollars.

a$.$ Find the revenue function in terms of $x.$

$R(x)=$

b$.$ Find the profit $($or loss$)$ earned at an output of $30$ Mini$-$Vacs.

c$.$ On your own, graph the revenue and cost. Be sure to mark the scale on both axes $($fit it to Revenue, which you should graph first$),$ label: $y=R(x),y=C(x),$ the break$-$even points, the $x-$intercepts of $y=R(x),$ and the $y-$intercept of $y=C(x).$

d$.$ According to your graph, what is the maximum revenue and at what output level does it occur?

Maximum revenue is $ at $x=$

$9.$

Perko manufactures and sells coffee cups. Graphs of the revenue and cost functions are shown below. Both revenue and cost are in dollars. If the fixed costs to manufacture the cups increases by $$100\mathrm{.}00,$ the cost function will change. Draw the new cost function on the graph.

Draw: