SOLUTION: How do I factorise: (a+b)^3-8b^3 Thank you

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Question 978898: How do I factorise:
(a+b)^3-8b^3
Thank you
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!

%28a%2Bb%29%5E3-8b%5E3  

write that as

%28a%2Bb%29%5E3-%282b%29%5E3

You need to know this factorisation:

X%5E3-Y%5E3%22%22=%22%22%28X%5E%22%22-Y%5E%22%22%29%28X%5E2%2BXY%2BY%5E2%29

Then substitute %28a%2Bb%29 for X and %282b%29 for Y
and simplify.

Now you can finish.  If you get stuck, you can tell me in
the thank-you note form below and I'll get back to you.

I do this for fun, not money.  So you don't have to pay.

Edwin