Hey there Sign in to join this conversationNew here? Join for free

How do i solve this equation?? C2

Announcements Posted on
    • Thread Starter
    • 2 followers
    Offline

    ReputationRep:
    4x-480x^-2=0
    howq do i solve? step by step? Thanks all!
    • 0 followers
    Offline

    ReputationRep:
    try multiplying by x^2
    • Thread Starter
    • 2 followers
    Offline

    ReputationRep:
    (Original post by Coulson72)
    try multiplying by x^2
    Okay sweet I got : 4x^3-480=0
    4x^3=480
    x^3=120
    x= 3 root 120 = 4.9...
    Thanks alot btw, but how do I choose what to multiply by if this was another q in an exam with different multiples...? Thanks though!!
    • 0 followers
    Offline

    ReputationRep:
    well if you get summit similar try multiplying by enough to turn the biggest negative into a 0, so like if you have 2x^2+5x^-3=0 then you'd try multiplying by x^3 to turn the -3 into a 0
    • 14 followers
    Offline

    ReputationRep:
    (Original post by alex7892)
    Okay sweet I got : 4x^3-480=0
    4x^3=480
    x^3=120
    x= 3 root 120 = 4.9...
    Thanks alot btw, but how do I choose what to multiply by if this was another q in an exam with different multiples...? Thanks though!!
    Well it's better to get rid of the fractions or negative power (by this I mean \dfrac{1}{x^2} or x^{-2}). So multiply by whatever you need to get rid of the negative power.
    • Thread Starter
    • 2 followers
    Offline

    ReputationRep:
    Thanks all great help. Love feeling confident about maths and getting it haha!!
    • 13 followers
    Offline

    ReputationRep:
    (Original post by alex7892)
    Okay sweet I got : but how do I choose what to multiply by if this was another q in an exam with different multiples...? Thanks though!!
    Suppose you have been given permission to drive your friends car. You are given a large bunch of keys. How do you KNOW which key to use?

    What would you do? I guess most people would try one key, then another and so on.

    It's the same with mathematics. JUST try and see what happens.

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?

    this is what you'll be called on TSR

  2. this can't be left blank
    this email is already registered. Forgotten your password?

    never shared and never spammed

  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By joining you agree to our Ts and Cs, privacy policy and site rules

  2. Slide the button to the right to create your account

    Slide to join now Processing…

Updated: April 22, 2012
New on TSR

Your favourite film of the year?

For you personally what has been the best 2014 movie

Article updates
Reputation gems:
You get these gems as you gain rep from other members for making good contributions and giving helpful advice.