The profit P in dollars that you earn from selling n cupcakes is given by . If you want your profit to be $7 how many cupcakes should you sell? Round to the nearest whole number.

Question

The profit P in dollars that you earn from selling n cupcakes is given by  . If you want your profit to be $7 how many cupcakes should you sell? Round to the nearest whole number.

Quizplus · Accepted Answer

We need to solve the equation 11ec19db_8522_439c_9dbe_b349d36b483a_TBX8673_11 = 7 for n. 
Substituting 7 for P, we get: 
11n - 0.005n^2 - 80 = 7 
Simplifying and rearranging: 
0.005n^2 - 11n + 87 = 0 
Using the quadratic formula: 
n = (11 ± sqrt(11^2 - 4(0.005)(87))) / (2(0.005)) 
n ≈ 15.8 or n ≈ 1.2 
Since we can't sell a fractional part of a cupcake, we round to the nearest whole number.
n ≈ 16 cupcakes will give us a profit of approximately $7.

The Profit P in Dollars That You Earn from Selling