Question 1037014
{{{P(x)=59x-0.4x^2-(3x+13)}}}


{{{P(x)=59x-0.4x^2-3x-13}}}
{{{highlight(P(x)=-0.4x^2+56x-13)}}}-----if you want in its general form.


Let x=90 and evaluate R, C, and P.   You can do all of that without a graphing calculator.  You might use Google as an alternative.  Just type into the search field,  y=-0.4x^2+56x-13, and drag inside the graph to what you want.