A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 4 years ago

Factor completely 3x3 – 21x2 – 27x

  • This Question is Closed
  1. anonymous
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    3x^3-21x^2-27x= 3x(x^2-7x-9)= =(x-(7+sqrt(85))/2) or (x-(7+sqrt(85))/2)

  2. anonymous
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    sry, 3x(x-(7+sqrt(85))/2) or 3x(x-(7+sqrt(85))/2)

  3. jagatuba
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \[3x(x ^{2}-7x-9)\]

  4. jagatuba
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    It is all about what you can evenly pull out of the expression. Start with x. How many x's can you pull from each term? Since 27x only has one x you can only pull one from the other two terms as well so that leaves you with: \[x(3x ^{2}-21x-27)\] Now what is the biggest factor that you can pull out of the numbers in each term. Since 3 is the smallest number it cannot be bigger than that. So check. Are the other numbers 21 and 27 divisibile by 3? Yep so lets pull 3 from each term: \[3/3=1, -21/3=-7, -27/3=-9\] SO now we have the factor that we pulled out (3x) times what we have left or: \[3x(x ^{2}-7x-9)\]

  5. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.