SOLUTION: factor 125x3 + 64y3

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Question 249567: factor 125x3 + 64y3
Answer by chosenpoint(26) About Me  (Show Source):
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Equations/249567 (2009-12-14 02:59:25): factor 125x3 + 64y3

You can use the following formula to factor the sum of 2 cubes:

(a^3+b^3)=(a+b)*(a^2–a*b+b^2)

In this specific case, a=5x and b=4y

Then we can easily substitute these into our formula

%285x%2B4y%29%2825x%5E2-5x%2A4y%2B16y%5E2%29

%285x%2B4y%29%2825x%5E2-20x%2Ay%2B16y%5E2%29 simplify and final answer

As a note, the difference of two cubes can be found using the following formula:

(a^3–b^3)=(a–b)*(a^2+ab+b^2)

Answer 181746 by chosenpoint(20) on 2009-12-14 04:59:57