Several college students live in an apartment building and share a washer and dryer. the cost of the rental, $20 per week, is shared evenly by the student who use the machines.

write a function that describes the weekly cost per student, in dollars, if x students use the machines.

c(x) =

, much appreciated.

  c(x) = 20/x

Step-by-step explanation:

The cost per student is the cost divided by the number of students. The cost is 20 and the number of students is x, so ...

   c(x) = 20/x . . . . . . . cost divided by the number of students

the 3rd on is correct

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