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)#