Question 1046314
{{{300=R-C}}}


{{{100x-0.5x^2-60x-300=300}}}


{{{40x-0.5x^2-600=0}}}


{{{0.5x^2-40x+600=0}}}


{{{x^2-80x+1200=0}}}
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discriminant, {{{(-80)^2-4*1200=6400-4800=1600=40^2}}};


{{{highlight(x=(80+- 40)/2)}}}