SOLUTION: How to solve 7x2=21x ? (seven x squared equals twenty-one x). The answer key says the answer is 0,3 but I do not how how they solved it. My educated guess is that I need to make th

Algebra ->  Equations -> SOLUTION: How to solve 7x2=21x ? (seven x squared equals twenty-one x). The answer key says the answer is 0,3 but I do not how how they solved it. My educated guess is that I need to make th      Log On


   

Question 448570: How to solve 7x2=21x ? (seven x squared equals twenty-one x). The answer key says the answer is 0,3 but I do not how how they solved it. My educated guess is that I need to make them both equal to zero but am not sure. Thank you for your help and look forward to hearing from you.
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
7x2=21x ? (seven x squared equals twenty-one x).
The answer key says the answer is 0,3 but I do not how how they solved it.
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7x^2-21x = 0
Factor:
7x(x-3) = 0
7x = 0 or x-3 = 0
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x = 0 or x = 3
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Cheers,
Stan H.
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