1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Factor: Y to the 4th power -81

  1. Dec 31, 2007 #1
    Please help! I dont know what to do
  2. jcsd
  3. Dec 31, 2007 #2
    oh and also 3x^2-6x-24
  4. Dec 31, 2007 #3
  5. Dec 31, 2007 #4
    Uhh please help me
  6. Dec 31, 2007 #5
    w/e I thought this was a help site
  7. Dec 31, 2007 #6
    i'll give you a hint since no one else will it's a difference of perfect squares
  8. Jan 1, 2008 #7


    User Avatar
    Science Advisor

    Yes, it is. Do you understand what "help" is? Did you bother to READ the file you were required to read when you registered? Did you read the part that says home-work must be posted on the "Homework" site? Did you read the part that says you MUST attempt the problem yourself so that we can see what kind of help you need. "Help" does not mean giving you the answer.

    For the first, as ice109 said, [itex]Y^4- 81[/itex] can be written in the form [itex]x^2- a^2[/itex] for correct values of x and a. Do you know the simple formula for [itex]x^2- a^2[/itex]?

    As for the second, [itex]3x^2-6x-24[/itex], the only way to factor [itex]3x^2[/itex] is (3x)(x). There are several ways to factor 24, what are they? Do you know how to use that information to find the factors of [itex]3x^2-6x-24[/itex]? I find it hard to believe that you were given a problem like this with no instruction or examples beforehand.
  9. Jan 1, 2008 #8


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    Do you think we are computers or something?
    In the space of 10 minutes you send off 5 requests.

    Do you think we are sitting here just yearning to read exactly your post, and then in jubilation answer it the second it arrives?
  10. Jan 1, 2008 #9
    New Years?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook