SOLUTION: The price of a screw is lowered by 1c.Before the reduction you could buy screws with 80c and get no change . Now you get one screw more and 3c change. Calculate the orignal price o

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Question 949323: The price of a screw is lowered by 1c.Before the reduction you could buy screws with 80c and get no change . Now you get one screw more and 3c change. Calculate the orignal price of one screw.
My solution:
Let x=price of each screw and Y= price of screws
Scenario 1. (X-1)
Scenario 2. ( Yx=80)
Scenario 3. (Y(x+1)=80-77)
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
The price of a screw is lowered by 1c.Before the reduction you could buy screws with 80c and get no change .
Now you get one screw more and 3c change.
Calculate the original price of one screw.
:
I think we can do this with one variable
:
let x = the price of one screw originally
then
(x-1) = lowered price of a screw
and
(80%2Fx%29 = original number of screws
:
77%2F%28%28x-1%29%29 = 80%2Fx + 1
multiply equation by x(x-1), resulting in
77x = 80(x-1) + x(x-1)
77x = 80x - 80 + x^2 - x
0 = x^2 - x + 80x - 77x - 80
x^2 + 2x - 80 = 0
Factors to
(x+10)(x-8) = 0
the positive solution all we want here
x = 8 cents for each screw originally
:
:
See of that checks out
Original number of screws: 80/8 = 10 each
Lower price by one cent; number of screws: 77/7 = 11 each