Question 1170314

{{{T(x)=-3x^2+240x-1800}}}

{{{T(x)=3000}}}

{{{3000=-3x^2+240x-1800}}}

{{{0=-3x^2+240x-1800-3000}}} 

{{{0=-3x^2+240x-4800}}} both sides multiply by {{{-1}}}

{{{0=3x^2-240x+4800}}}

{{{0=3(x^2-80x+1600)}}}

{{{0=3(x^2-80x+40^2)}}}

{{{0=3(x-40)^2)}}}

=>{{{x=40}}}

answer: {{{40}}} microwaves must be produced and sold to achieve a profit of ${{{3000}}}