SOLUTION: 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? (Hint: "$50 lo

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: 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? (Hint: "$50 lo      Log On


   

Question 64303: 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? (Hint: "$50 loss" means a "negative $50 profit". Plug in -50 for P and solve for x)
Answer by chitra(359) About Me  (Show Source):
You can put this solution on YOUR website!
The expression for profit is given by:

P = x^2 – 13x – 80 where x represents the number of watches.

By data, it is told that on a particular day there was a loss of $50. That is a negative profit.

That is P = - $ 50

Substituting for P in the above equation, we get:

-50+=+x%5E2+-+13x+-+80

Adding 50 on both sides of the above equation, we get:

x%5E2+-+13x+-+80+%2B+50+=+0

x%5E2+-+13x+-+30+=+0

x%5E2+-+10x+-+3x+-+30+=+0

Taking the first two terms and then grouping them again, we get:

x%28x+-+10%29+-+3%28x+-+10%29+=+0

Taking common factors again, we get:

(x - 3)(x - 10) = 0

So, (x - 3) = 0 OR (x - 10) = 0

Therefore, x = 3 OR x = 10

Therefore, x = 3 or x = 10

Hence, the solution.