If, in a monopoly market, the demand function for a product is p = 130 − 0.50x
and the revenue function is
R = px,
where x is the number of units sold and p is the price per unit, what price will maximize revenue?

The correct answer is $90

Thats where they was ported and the fields that noone really knew much about needed tended, so they put slaves out there do free work and huge profits and so on the north decided to hold its own and was more different way of survival did not have same climate conditions to afford protecting slaves from winter so expenses be diff from south