Question 1122339
Every additional 1 card sold, price decrease $0.05.

Known point,  (6, 280).
x is price, p is ... number of cards sold.


{{{p=-0.05x+b}}}
{{{b=p+0.05x}}}
{{{b=280+0.05*6}}}
{{{b=286}}}


{{{p=-0.05x+286}}}



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( I may have mixed up the meaning of the variables . )