9units sorry for not showing work though but glad I can help
Call the production cost 'C', the revenue 'R' and the number of CDs 'n':
C=2000+5n
R=10n
By definition Profit P = R-C, therefore P=10n-2000+5n = 5n-2000.
3.5*(-3)///////3.5*(-3)//////all of this parts same
You can find the area of a triangular prism by putting it into a bet and finding the area of all sides then adding them together