Chapter 8 - Review - Page 621: 33

a) 119 dollars b) 77 dollars c) As the number of bookcases increases, the average cost decreases.

$C(x)=\frac{35x+4200}{x}$ a) $x=50$ $C(x)=\frac{35x+4200}{x}$ $C(50)=\frac{35*50+4200}{50}$ $C(50)=(1750+4200)/50$ $C(50)=5950/50$ $C(50)=119$ b) $x=100$ $C(x)=\frac{35x+4200}{x}$ $C(100)=\frac{35*100+4200}{100}$ $C(100)=(3500+4200)/100$ $C(100)=7700/100$ $C(100)=77$