SOLUTION: Ok so i've done this problem at least 20 times and i don't know what i am doing wrong! The work seems to be right, but every time that i have done it, it does not check out properl

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equation Customizable Word Problems -> SOLUTION: Ok so i've done this problem at least 20 times and i don't know what i am doing wrong! The work seems to be right, but every time that i have done it, it does not check out properl      Log On


   

Question 391733: Ok so i've done this problem at least 20 times and i don't know what i am doing wrong! The work seems to be right, but every time that i have done it, it does not check out properly. Please help!
Question: If the square of a positive number is decreased by twice the number the result is 15. Find the number.
Thank you!
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
If the square of a positive number is decreased by twice the number the result is 15. Find the number.
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Equation:
x^2-2x = 15
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x^2-2x-15 = 0
Factor:
(x-5)(x+3) = 0
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Positive solution:
x = 5
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Check:
5^2-2*5 = 15
25-10 = 15
15 = 15
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Cheers,
Stan H.
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