SOLUTION: Factor 8r^3-27

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Question 567518: Factor
8r^3-27
Answer by jim_thompson5910(23764) About Me  (Show Source):
You can put this solution on YOUR website!

8r%5E3-27 Start with the given expression.


%282r%29%5E3-%283%29%5E3 Rewrite 8r%5E3 as %282r%29%5E3. Rewrite 27 as %283%29%5E3.


%282r-3%29%28%282r%29%5E2%2B%282r%29%283%29%2B%283%29%5E2%29 Now factor by using the difference of cubes formula. Remember the difference of cubes formula is A%5E3-B%5E3=%28A-B%29%28A%5E2%2BAB%2BB%5E2%29


%282r-3%29%284r%5E2%2B6r%2B9%29 Multiply

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Answer:
So 8r%5E3-27 factors to %282r-3%29%284r%5E2%2B6r%2B9%29.

In other words, 8r%5E3-27=%282r-3%29%284r%5E2%2B6r%2B9%29