9. In this problem, p is in dollars and x is the number of units. If the demand function for a product is p = 28/(x + 1) and the supply function is p = 1 + 0.2x, find the consumer's surplus under pure competition. (Round your answer to two decimal places.)

wheres graph

step-by-step explanation:

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4