Question 166178
The number of footballs sold is,
{{{N=3000-150q}}}
The price for each football is {{{q}}}.
The total revenue is just the number of footballs sold multiplied by the price of each football. 
{{{R(q)=(3000-150q)q}}}
{{{R(q)=-150q^2+3000q}}}
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When q=$8, then 
{{{R(q)=-150q^2+3000q}}}
{{{R(8)=-150(8)^2+3000(8)}}}
{{{R(8)=-150(64)+24000}}}
{{{R(8)=-9600+24000}}}
{{{R(8)=14400}}}
The weekly revenue when footballs are $8 a piece is $14,400.