Question

-4x^3 – 16x^2 + 20x

Answer 1

What do you want to do in this?

Answer 2

I need to factor it.

Answer 3

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Answer 4

Okay..

Answer 5

This is what I have so far:
-4x^3(x^2 + 4x + 20)
_4x(x + 4)(x - 5)

Answer 6

i am lost after that

Answer 7

Firstly factor out -4x:

\[-4x(x^2 + 4x - 5)\]

Split the middle term:


\[-4x(x^2 + 5x - x - 5)\]

\[-4x(x+5)(x-1)\]

Answer 8

-4x^3 - 16x^2 + 20x
-4x(x^2 + 4x - 5)
-4x(x +4)(x -5)

Answer 9

@rwilson when you factored out -4x..the +20x should turn into -5 NOT +5x

Answer 10

there is still an x associated with the 5 even though the -4 already has one and the 5x is not squared?

Answer 11

so it should look like this:
-4x^3 - 16x +20x
-4x(x^2 + 4x -5) (right?)
(-4x)(x+5)(x-1)