## Calculus with Applications (10th Edition)

$C(x)=0.99x+10$
In a cost function of the form $C(x)=mx+b$, m represents the marginal cost and b represents the fixed cost. b= $\$ 10$(fixed cost) and m=$\$0.99$ (the cost per downloaded song). Let $x=$ the number of downloaded songs and $C(x)=$ cost of downloading $x$ songs. $C(x)=$ (marginal cost)(number of downloaded songs) + fixed cost $C(x)=0.99x+10$