could someone show me what i did wrong?

Question

Factor the polynomial completely.

−3x⁹−81x⁶

 

-3x^3 (x^6+27x^3) <<<< this was my answer but i got it wrong. what did i do wrong? 

Answer 1

Hello Jared,

 

While you did factor the polynomial, you did not factor completely.

 

In order to factor completely the x⁶ +27x³ should have nothing in common, but they do... x³ .

 

In your answer you only factored out -3x³ and needed to factor out -3x⁶ instead and make the necessary changes inside the parenthesis.  After doing that you will notice that you can use your rule for factoring the sum of cubes a³ + b³ = (a + b)(a² – ab + b²) to break it down even more!

 

I hope that helps.

 

Answer 2

Let's look at a step by step process on how to get the right answer, and then we can speculate on where you went wrong.

 

1) Given: -3x^9-81x^6

2) Pull out common terms (another way to describe factoring): -3x^6(x^3+27)

3) Speculation time: It looks like you just missed that you should be pulling out as many X's as you can. Do you see how you can pull x^3 out of the quantity inside the ( ) still?

4) Celebrate knowing now what to do next time!