SOLUTION: You know that subtracting 15 times a number from twice the square of the number results in an answer of -27. How do I write the equation to represent this?

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: You know that subtracting 15 times a number from twice the square of the number results in an answer of -27. How do I write the equation to represent this?      Log On


   

Question 94078: You know that subtracting 15 times a number from twice the square of the number results in an answer of -27. How do I write the equation to represent this?
Found 2 solutions by checkley75, bucky:
Answer by checkley75(3666) About Me  (Show Source):
You can put this solution on YOUR website!
2X^2-15X=-27
2X^2-15X+27=0
(2X-9)(X-3)=0
2X-9=0
2X=9
X=9/2
X=4.5 ANSWER.
X-3=0
X=3 ANSWER.

Answer by bucky(2189) About Me  (Show Source):
You can put this solution on YOUR website!
Let x be the unknown number.
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Then twice the square of this number is 2x%5E2
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15 times the number is 15x. Subtracting this from twice the square of the number is:
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2x%5E2+-+15x
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And you are told that this has to equal -27.
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Therefore, the equation you are looking for is:
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2x%5E2+-15x+=+-27.
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Just in case you work out this equation, it has two solutions ... x+=+9%2F2 and x+=+3
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Hope this is of some assistance to you.