Question 1109814

{{{R(x) = 9x - 0.01x^2}}}

if {{{R = xp}}} , we have

{{{xp = 9x - 0.01x^2}}}

{{{p = 9x/x - 0.01x^2/x}}}

{{{p = 9 - 0.01x}}}

the price they should charge if they want to sell {{{420}}} items per day will be:

{{{p = 9 - 0.01*420}}}

{{{p = 9- 4.2}}}

{{{p =  4.8}}}