factor 5x cubed minus 45x

Question

factor 5x cubed minus 45x

Answer 1

Start with: 5x³ - 45x.

 

You can factor out every term starting with constants; in this case 5.

 

5 ( x³ - 9x)

 

Next step, factor out the x so

 

5x (x² - 9)

 

Using FOIL, you can then factor out the term in the parenthesis (x² - 9). Note there is no x term and the 9 is a perfect square. You get (x -3) (x + 3).

 

So, in its final form you get

 

(5x )(x - 3) (x + 3)

 

which can also be written as

 

5(x)(x-3)(x+3)