SOLUTION: the revenue R in dollars for the sale of x items at Joe's Dollar Store can be modeled by the equation R=1400x-5x^2. what number of items would provide a revenue of $16,080?

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: the revenue R in dollars for the sale of x items at Joe's Dollar Store can be modeled by the equation R=1400x-5x^2. what number of items would provide a revenue of $16,080?      Log On


   

Question 134543: the revenue R in dollars for the sale of x items at Joe's Dollar Store can be modeled by the equation R=1400x-5x^2. what number of items would provide a revenue of $16,080?
Found 2 solutions by vleith, checkley71:
Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
Given : R=1400x-5x%5E2
what number of items would provide a revenue of $16,080?
R=1400x-5x%5E2
16080+=+1400x-5x%5E2
3216+=+280x+-+x%5E2
0+=+x%5E2+-+280x+%2B+3216

Use the quadratic equation
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
(280 -+ 256)/2
x = 12 , 268
Check answers

Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
R=1400X-5X^2
16,080=1400X^2-5X^2
5X^2-1400X+16,080=0
5(X^2-280X+3216=0
5(X-268)(X-12)=0
X-268=0
X=268 ANSWER.
X-12=0
X=12 ANSWER.