SOLUTION: Hello, I am stuck on factoring 1331c^3 + 512d^3 I started with cube roots 11 and 8 (11c+8d)(11c^2-(11c)(8d)+8d^2) This is where I get stuck. Thanks in advance for a

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Hello, I am stuck on factoring 1331c^3 + 512d^3 I started with cube roots 11 and 8 (11c+8d)(11c^2-(11c)(8d)+8d^2) This is where I get stuck. Thanks in advance for a      Log On


   



Question 227530: Hello, I am stuck on factoring 1331c^3 + 512d^3

I started with cube roots 11 and 8
(11c+8d)(11c^2-(11c)(8d)+8d^2)
This is where I get stuck.
Thanks in advance for any help

Found 2 solutions by Alan3354, jsmallt9:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
1331c^3 + 512d^3
I started with cube roots 11 and 8
(11c+8d)(11c^2-(11c)(8d)+8d^2)
You have it almost right.
= (11c+8d)[(11c)^2 - 11c*8d + (8d)^2] Square the whole term, not just the variables.
= (11c+8d)(121c^2 - 88cd + 64d^2)

Answer by jsmallt9(3758) About Me  (Show Source):
You can put this solution on YOUR website!
The reason you're stuck is that you're finished (except to simplify the second factor)!

Whenever you factor you should start by factoring out the Greatest Common Factor (GCF) if it is not a 1. As long as you do this, the second factor of the Sum (or Difference) of Cubes pattern is inherently unfactorable. In other words, as long as the GCF has been taken care of, there is never a point in trying to factor the a%5E2+-+ab+%2B+b%5E2 factor. (If you don't believe me, try to factor a%5E2+-+ab+%2B+b%5E2! You won't succeed unless you use irrational numbers.)

Your GCF is 1 so: