6 + 3c is the correct answer
![431 \div 9](https://tex.z-dn.net/?f=431%20%5Cdiv%209%20)
=47.8888 when you round it up you can get get about 48 then you estimate to about 50.
The surface area is 54 square inches
Http://www.madeiracityschools.org/userfiles/376/Classes/17052/Review%20Worksheet%20Unit%209%20Quiz%2...
I would use this website. Hope it helps!