Chapter 1 - Section 1.2 - Functions and Models - Exercises - Page 74: 43c

$N(20)$ is the cost of removing $20$ pounds of PCP's per day, after receiving the subsidy from the government. $N(20)={{\$}} 32,000$

$N(20)$ is the cost of removing $20$ pounds of PCP's per day, after receiving the subsidy from the government. $N(20)=100(20^{2})-500(20)+2000$ $=40,000-10,000+2000$ $=32,000$