Given the Following Revenue and Cost Functions, Find the X-Value $R ( x ) = 84 x - 2 x ^ { 2 } ; C ( x ) = 22 x + 101$

Multiple Choice

Given the following revenue and cost functions, find the x-value that makes revenue a maximum. $R ( x ) = 84 x - 2 x ^ { 2 } ; C ( x ) = 22 x + 101$

A) 22
B) 21
C) 20
D) 42