How do you factor completely 3a^3 - 27ab^2?

2 Answers
Mar 17, 2018

3a ( a^2 - 9b^2)

Explanation:

3a^3 - 27ab^2

Since both numbers (3 and -27) can be factored by 3, let's take the 3 out:
3 ( a^3 - 9ab^2)

Again, since both letters (a^3 and a) have a's in them, let's take the "a" out too! And remember, you can only take out 1 "a" because if you take out 2, there aren't 2 a's on the left group.
3a ( a^2 - 9b^2)

After that, there is nothing else you can simplify. So, here's your answer:
3a ( a^2 - 9b^2)

Hope this helps!! :)

Mar 17, 2018

3a  (a + 3b)( a - 3b)

Explanation:

Factor   3 a^3−27 a b^2

1) Factor out 3a from each term

3a (a^2 - 9  b^2)

2) Factor the Difference of Two Squares

3a  (a + 3b)( a - 3b)