How to find the maximum revenue for this problem? Please show all steps:

Question

Hello - I need to how to solve find the maximum revenue for this problem and I need to be able to show all of the steps.  Here is the problem:  Thank You - tsj

R = -x^2/7 + 82x - 310

Answer 1

R = - x^2/7 + 82x - 310

x = - B/2A =  - 82/( - 2/7)  =  82*7/2 =    287

R = -287^2/7+ 82*287 - 310

R = 15057

max' ( 287, 15057 )

Comments

Thank you so very much!!!  However, I do not understand how -287^2/7 + 82*287 - 310 = 15057.  I have tried to do it over, over and when I do -287^2 I get 82369 and when I divide this by 7 I get 11767, then 82*287 is 23534 + 11767 - 310 is 34991..... Can you please tell me where I am going wrong with this?