Page 1 of 3 123 LastLast
Results 1 to 15 of 44

Thread: Maths help.

  1. #1
    International Captain cover drive man's Avatar
    Join Date
    Dec 2006
    Location
    Liverpool, England
    Posts
    7,103

    Maths help.

    I always get stuck on these type of equations, could anyone find me an easy way to work them out.

    The equations;

    5x-2=x+10

    5x-2=3x+1

    3(x+4)=x-5

    5(x-2)=2(x+4)







    Shameful I know, but I have my reasons.
    Everyone wants to change the world, noone wants to change himself.

    -Tolstoy

  2. #2
    International Regular Steulen's Avatar
    Join Date
    Aug 2004
    Location
    Clydeside Cloggie
    Posts
    3,189
    dude, these are way too simple.

    move all X's to one side of the equation and all loose terms to the other, and bingo.

    for instance, the first one:

    5x - 2 = x + 10
    5x -x = 10 + 2
    4x = 12
    x = 3
    President of RTDAS - Ryan ten Doeschate - The Freddie Flintoff of Associate Cricket
    Member of DNAS, ESAS - Dirk Nannes, Edgar Schiferli. Dutchmen can bowl.

    Quote Originally Posted by Pedro Delgado
    Steulen, are you half-Welsh? Cheer up.
    Quote Originally Posted by Matt79
    God, I just worked out Steulen's avatar is a hedgehog, not a brain...
    Not sure how to feel now tbh...

  3. #3
    International Captain cover drive man's Avatar
    Join Date
    Dec 2006
    Location
    Liverpool, England
    Posts
    7,103
    Also this simultaneous equation:

    5x+3y=8
    3x-y=9




    I know this is pathetic but still.

  4. #4
    Eternal Optimist / Cricket Web Staff Member GIMH's Avatar
    Join Date
    Dec 2005
    Location
    Jason Koumas is having a party
    Posts
    48,093
    5x=x+8

    5x=3x+3

    3x+7=x

    5x=2x+18



    I have done some quick cancelling out for you that may well be wrong as I am only on a quick break. Let me know if that helps, it should make things a bit simpler.

    basically the first thing you need to do is balance the equation. If you have something saying x+ 7= 3x+19, take 7 off both, ie x=3x+12. Thinking about it now it seems a ridiculously bad example, but hopefully you see what I mean

    All this being said, there are plenty of maths geeks here better than me
    "It was an easy decision to sign. I could have gone elsewhere, I had calls, but it never entered my mind it's not about the money."
    Jason Koumas

    SWA

    RIP Craigos. A true CW legend. You will be missed.


  5. #5
    International Captain cover drive man's Avatar
    Join Date
    Dec 2006
    Location
    Liverpool, England
    Posts
    7,103
    Quote Originally Posted by Steulen View Post
    dude, these are way too simple.

    move all X's to one side of the equation and all loose terms to the other, and bingo.

    for instance, the first one:

    5x - 2 = x + 10
    5x -x = 10 + 2
    4x = 12
    x = 3
    Thanks, and I know these are easy but when you've been off school for months you forget things.

  6. #6
    Eternal Optimist / Cricket Web Staff Member GIMH's Avatar
    Join Date
    Dec 2005
    Location
    Jason Koumas is having a party
    Posts
    48,093
    There is nothing pathetic about being stuck, or needing help, cdm

  7. #7
    Eternal Optimist / Cricket Web Staff Member GIMH's Avatar
    Join Date
    Dec 2005
    Location
    Jason Koumas is having a party
    Posts
    48,093
    And it seems my method is wrong, jeez shows you how lnog it's been since I learned these things

  8. #8
    The Wheel is Forever silentstriker's Avatar
    Join Date
    Feb 2006
    Location
    USA
    Posts
    37,667
    Instead of asking us to do the homework, you should post the question, and then show your attempt at a solution.

    There are steps to solving systems of equations. List them, and try to follow them. Show your work, and then ask when you are stuck. You're not going to learn how to do it by having us do your homework.
    Quote Originally Posted by KungFu_Kallis View Post
    Peter Siddle top scores in both innings....... Matthew Wade gets out twice in one ball
    "The future light cone of the next Indian fast bowler is exactly the same as the past light cone of the previous one"
    -My beliefs summarized in words much more eloquent than I could come up with

    How the Universe came from nothing

  9. #9
    International Captain cover drive man's Avatar
    Join Date
    Dec 2006
    Location
    Liverpool, England
    Posts
    7,103
    Quote Originally Posted by Steulen View Post
    dude, these are way too simple.

    move all X's to one side of the equation and all loose terms to the other, and bingo.

    for instance, the first one:

    5x - 2 = x + 10
    5x -x = 10 + 2
    4x = 12
    x = 3
    I tried that on the second one I did.

    5x-3x=-2+1
    2x=-1
    x=-0.5


    Thats wrong though, what did I do wrong?

  10. #10
    International Regular Steulen's Avatar
    Join Date
    Aug 2004
    Location
    Clydeside Cloggie
    Posts
    3,189
    these are a little harder, because with two unknowns you have to balance both equations in such a way that one of the unknowns gets cancelled out.

    So:

    5x + 3y = 8
    3x - y = 9

    let's first move all non-x terms to the right of the equations:

    5x = 8 - 3y
    3x = 9 + y

    then make sure both x terms are equal, by multiplying the first equation by 3,, and the second equation by 5:

    15x = 24 - 9y
    15x = 45 + 5y

    this means that 24-9y = 45+5y, as they both equal 15x.

    you can then do the same thing as with the earlier equation where you only has to solve X:

    -9y - 5y = 45 -24
    -14y = 21
    y = -1.5

    Then substitute this value for y in any of the two original equations to find x;

    5x + (3*-1.5) = 8
    5x - 4.5 = 8
    5x = 12.5
    x = 2.5

  11. #11
    International Regular Steulen's Avatar
    Join Date
    Aug 2004
    Location
    Clydeside Cloggie
    Posts
    3,189
    Quote Originally Posted by cover drive man View Post
    I tried that on the second one I did.

    5x-3x=-2+1
    2x=-1
    x=-0.5


    Thats wrong though, what did I do wrong?
    if you move -2 to the other side, it becomes +2.

  12. #12
    International Captain cover drive man's Avatar
    Join Date
    Dec 2006
    Location
    Liverpool, England
    Posts
    7,103
    Quote Originally Posted by Steulen View Post
    if you move -2 to the other side, it becomes +2.
    So,

    5x-3x=2+1
    2x=3
    x=1.5

  13. #13
    International Captain cover drive man's Avatar
    Join Date
    Dec 2006
    Location
    Liverpool, England
    Posts
    7,103
    Quote Originally Posted by cover drive man View Post
    3(x+4)=x-5

    5(x-2)=2(x+4)
    What about these ones, do you expand the brackets?

  14. #14
    The Wheel is Forever silentstriker's Avatar
    Join Date
    Feb 2006
    Location
    USA
    Posts
    37,667
    Remember PEMDAS. Try it out, and post your attempt. We'll help you out, but you should try it first. We'll correct what you get wrong, it's the best way to learn.
    Last edited by silentstriker; 23-04-2009 at 08:13 AM.

  15. #15
    International Captain cover drive man's Avatar
    Join Date
    Dec 2006
    Location
    Liverpool, England
    Posts
    7,103
    I got this

    3(x+4)=x-5
    3x+12=x-5
    3x-x=-5-12
    2x=-17
    x=-8.5

Page 1 of 3 123 LastLast


Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. The School Thread
    By Jakester1288 in forum Off Topic
    Replies: 549
    Last Post: 19-09-2011, 05:26 AM
  2. Does 0.9r = 1?
    By PhoenixFire in forum Off Topic
    Replies: 66
    Last Post: 23-04-2009, 05:57 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •