SOLUTION: 5x3 + 40y6

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Question 623751: 5x3 + 40y6

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
5x%5E3%2B40y%5E6 What would you like to do with this expression?
Factor it, perhaps? Ok, but please include some instructions next time!
Factor:
5x%5E3%2B40y%5E6 Factor a 5 then rewrite this as:
5%28x%5E3%2B8y%5E6%29 Do you recognise the factor in parentheses as the sum of two cubes?
5%28%28x%29%5E3%2B%282y%5E2%29%5E3%29
The sum of two cubes is factorble as:
A%5E3%2BB%5E3+=+%28A%2BB%29%28A%5E2-AB%2BB%5E2%29 where: A+=+x and B+=+2y%5E2 so we have:
5%28x%2B2y%5E2%29%28x%5E2-2xy%5E2%2B4y%5E4%29