Question 103720
The profit on a watch is given by {{{p=x^2-13x-80}}} Where x is the number of watches sold per day. How many watches were sold on a day when there was a $50 loss?
Since there was a $50 loss, the profit would be -50
{{{-50 = x^2-13x-80}}}
{{{0=x^2-13x-80+50}}}
{{{0=x^2 - 13x-30}}}
0=(x+2)(x-15)
x+2=0
x=-2
x-15=0
x=15
It says they sold some watches, so the answer would need to be 15.
:)