Algebra Yikes!

Discussion in 'Odds & Ends' started by bluestreak711, Sep 10, 2007.

  1. bluestreak711

    bluestreak711 Rookie

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    Is there a forum with homework help or can someone help me here?:confused:



    (Please see last page on forum.)
     
    Last edited: Nov 26, 2007
    #1
  2. forzainter

    forzainter Semi-Pro

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    try bbc bitesize, type into google 'bbc scotland bitesize' and then go into maths and if you are 14 - 15 - 16 click standard grade and if you are older click higher or advanced higher
     
    #2
  3. ilovecarlos

    ilovecarlos Professional

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    Lotsa luck there...it took me 2 years to pass algebra (geometry is MUCH easier) and I'll tell you what....I've never ever used it...I do not care what
    x =........it should be abolished...along with those, "two trains leave different stations at the same time" problems....Hey, I know..let's ban math period!!!;)
     
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  4. Kobble

    Kobble Hall of Fame

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    Math for the sake of math had driven me crazy before college. Schools need to show people how to apply what they have learned. Check the web, though. You can find sites that break it down for you with good anaologies. My advice, learn the applications and it will stick better. Otherwise it is like learning a language without the intention of speaking it.
     
    #4
  5. lethalfang

    lethalfang Professional

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    Are you the President by any chance?
     
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  6. xtremerunnerars

    xtremerunnerars Hall of Fame

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    Post problems you have trouble with and someone (I'll help when it's something I know) will help you out.
     
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  7. Mastermind

    Mastermind Rookie

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    LMFAO @ lethal fang. :D


    To the OP: if you can type it down I can probably help you, algebra isn't hard and I've taken Calculus.
     
    #7
  8. diegaa

    diegaa Hall of Fame

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    ditto, it has happened before.
    i had 2 courses of algebra and 3 calculus. I almost dont recall anything, but like mastermind said, it isnt that hard.
     
    Last edited: Sep 10, 2007
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  9. xtremerunnerars

    xtremerunnerars Hall of Fame

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    Exactly: it's all relative. What's hard for you at age 11 is a joke when you're 18. I never really got how most tests could be hard because a lot of stuff you know it or you dont. Some things take a while and others demand a lot, but there's a pretty solid correlation between less intelligent people and how much they say stuff is hard.

    Be glad if stuff comes naturally!
     
    #9
  10. dave333

    dave333 Hall of Fame

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    I'm takin AP Calc right now as a sophmore and lemme tell ya, if you have trouble with algebra (I breezed through it), you're in for a hell of a time.

    Its a lot harder than pre-cal, alg II, alg but could be worse I guess.
     
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  11. shojun25

    shojun25 Professional

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    Wow, did you skip a grade or two? Because I'm a junior taking AP Calc, no sophomores at all.

    By the way, did you start derivatives and limits? So far, Calc has been easy (can't say the same for the teacher).

    And to the OP, algebra isn't really hard. Write down the problem and I'll try to help you with it (if I remember).
     
    #11
  12. Noveson

    Noveson Hall of Fame

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    Naw AP Calc is nothing, well now, last year it was very hard;) Though I had a much harder time with Geometry than anything I have had afterwards. Oh and AP US History is just insane. I hate it so much.....
     
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  13. Noveson

    Noveson Hall of Fame

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    Yeah, I took it as a sophomore too, and I'm not like a genius or anything lol. Must just be what school you're in, because here AP Calc as a sophomore is for the pretty damn smart kids, but it's not like super unusual.
     
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  14. bluestreak711

    bluestreak711 Rookie

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    Two missing factors
    3x+4y=1
    2x+2y=1

    and for future reference how would i type brackets
     
    #14
  15. bluestreak711

    bluestreak711 Rookie

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    i searched for this specific kind of problem and it just returned two results

    Two missing factors.

    and i don't have a use for algebra unless i do take triginomitry or physics

    beacsue when that is learned you can apply equations to tennis

    and if all works well that is what i'll do

    p.s. if i don't need but one between trig and physics i won't take but one
     
    #15
  16. Court_Jester

    Court_Jester Hall of Fame

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    Multiply the 2nd eqtn by -2 and you'll get the ff:

    3x + 4y = 1
    -4x -4y = -2

    Add the two equations together to solve for x:

    -x = -1

    or

    x = 1

    Using this value for x, substitute this in either of the first two equations to solve for y (I'll use the 1st one):

    3(1) + 4y = 1 => 4y = -2

    or

    y = -1/2


    Solving systems of linear equations is so easy! :D
     
    #16
  17. bluestreak711

    bluestreak711 Rookie

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    ouch idk if i got a bit of that but my work book went from a problem like



    5x+7=8x+4

    5x-5x+7-4=8x+4-4-5x

    7-4=8x-5x

    3=3x

    3.....3x
    - = .. -
    3......3

    1=x


    to something like that last problem and i am lost
     
    Last edited: Sep 10, 2007
    #17
  18. Court_Jester

    Court_Jester Hall of Fame

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    Just messin' with ya! This happens to be one of my favorite math topics when I was in high school.


    You did this one correctly, for what it's worth.
     
    #18
  19. tennishead93

    tennishead93 Semi-Pro

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    gifted geometry sux
     
    #19
  20. bluestreak711

    bluestreak711 Rookie

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    well i didnt mean the problem i just did that i finally got that but the one with two equations i didnt understand a word
     
    #20
  21. Court_Jester

    Court_Jester Hall of Fame

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    Oh,...

    That problem you listed is what is called system of linear equation. There is a solution if the number of unknown variables (here, x and y) is equal to the number of equations given. The trick is to multiply one of the equations by a number so that when you add it to another one, one of the variables will be eliminated, thus simplifying the system to the point that you can solve for remaining variable.
     
    #21
  22. Tennis_Gnat

    Tennis_Gnat Rookie

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    Well......let's put it this way.

    the 8x and the 5x are numbers that can be added and subtracted. Same with the 4 and the 7. you CANNOT add/subtract say 4 with 8x.

    You want to solve for x. You want x to stand alone. So you need to combine the x terms.

    It's also easier if you combine the non-x terms.

    personally i think the way that's put is a bit confusing this is what i would write:

    5x + 7 = 8x +4
    5x goes across the river and changes signs (or gets subtracted off both sides....)
    5x - 5x = 8x -5x + 4

    OR (same thing, whichever makes more sense to you)

    7 = 8x + 4 - 5x
    (7 = 8x - 5x + 4)

    7= 3x + 4

    now the 4 goes across the river and changes signs

    7-4 = 3x
    3 = 3x
    3/3 = x
    1 = x

    Now I feel intelligent again. thanks. ;)
     
    #22
  23. bluestreak711

    bluestreak711 Rookie

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    Go on........
     
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  24. ffrpg

    ffrpg Professional

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    Alright, let's look at your two equations.
    3x+4y=1
    2x+2y=1


    The idea is to find a common factor for your X and Y values. Y was solved for you earlier and the Y values have a common factor of 4. What is the common factor for X? 6 is the common factor for X because 3x and 2x are multiples of 6. Let's pretend you don't know that Y is equal to -1/2 and lets try to eliminate the X from both equations. 3x+4y=1 becomes 6x+8y=2. 2x+2y=1 becomes 6x+6Y=3. Remember that 6 is the common factor for X, so we multiply everything in the first equation by 2 and everything in the second equation by 3. Now that both equations have 6x, we can subtract the two equations and eliminate the X variable.

    ''' 6x+8y=2 (ignore the '''. It won't space properly unless I use them)
    - 6x+6y=3
    ____________
    2y=-1

    divide the 2 and you get y=-1/2. Then you can plug that into your original first equation and you'll get 3x+4(-1/2)=1. That becomes 3x-2=1. Add two to the other side and you get 3x=3. Divide the 3 to isolate the x and you get x=3/3 which is x=1. It's pretty hard to show this online. Go ask someone to show you in person. Once you get the hang of it, it is really easy.
     
    #24
  25. Court_Jester

    Court_Jester Hall of Fame

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    Let's take the problem you listed earlier:

    3x + 4y = 1
    2x + 2y = 1

    You have a choice here, whether you want to eliminate the x first or the y. The question is how can we eliminate one of them. Let's say that we want to get rid of y first. Simply adding the two equations will not eliminate the y variable. However, if we multiply the 2nd equation by -2, the two equations will look like this:

    3x + 4y = 1
    -4x - 4y = -2

    Note that any multiplier number other than -2 will not eliminate the y variable after adding the two equations. Now, by adding the two equations, note that the terms containing y will cancel out, leaving you with one equation with one unknown, the x variable.

    3x - 4x + 4y - 4y = 1 - 2

    or

    -x = -1

    You have now reduced the system of two linear equations to a single equation with one unknown, which can then be solved easily to give:

    x = 1

    Now that you have the value for x, substitute this value into either one of the original equations and you'll be able to solve for thte y variable. As a check, substitute the x and y values that you have obtained into any one of the equations. The value of the left hand side should equal the one on the right hand side.

    Hope this clears it up.
     
    #25
  26. Court_Jester

    Court_Jester Hall of Fame

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    bluestreak711,

    ffrpg offers an alternative solution. In his case, he chose to eliminate the x variable first (I chose the y). As you can see, we both came up with the same solution.
     
    #26
  27. bluestreak711

    bluestreak711 Rookie

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    cool i think i got it

    now all i gotta do is practice similar equations for a couple weeks and go on to the next step

    so i will be back that is for sure

    and by the way

    the only person i know that can show me in person showed me

    how to solve the equation=equation

    with one variable on each side

    but after i showed him the next step he didnt have a clue(the one yall just showed me that is)

    anyway wish me luck

    too bad i didnt get this much help when i post a thread on my tennis game
     
    #27
  28. Duzza

    Duzza Legend

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    Wow....I did that in my head mate, come on! Give us something harder!
     
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  29. psp2

    psp2 Banned

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    Here's another easy one for you, Duzza.......

    What's the value of (1-i)^12, where i is the sqrt(-1)?

    Let's see you expand that in your head :)
     
    #29
  30. The_1337

    The_1337 New User

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    ^i think you could with pascals triangle.

    anyways, dont you learn this stuff in school? i always found that listening to the teacher will allow you to remember how to do everything.
     
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  31. lorenza

    lorenza Semi-Pro

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    umm -64? i was bored and that's what i got, but i might have messed up somewhere with my negatives :)
     
    #31
  32. Trainer

    Trainer Semi-Pro

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    Damn, this stuff is nauseating. And I'm going to have to learn it again when my daughter starts it in 2 years....
     
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  33. jinsol

    jinsol New User

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    lmao Trainer
    idk geometry sucks since right now were doing pointless conditionals, conjectures, etc.
    or
    If right now were doing pointless conditionals, conjectures, etc., then geometry sucks. doesn't seem false to me...:)
    its so boring we have to write it ALL out...
     
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  34. beernutz

    beernutz Hall of Fame

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    www.algebra1.com

    This is more helpful if you are actually using one of the textbooks related to this site but even if not there is some good stuff on them.
     
    #34
  35. bluestreak711

    bluestreak711 Rookie

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    ok is this correct?

    7x+10y=2
    4x+8y=9

    28x+40y=8
    28x+56y=63

    -16y=-55

    -16y/-16=-55/-16

    y=3.4375

    7x+10(3.4375)=2

    7x+34.375=2

    7x+34.375-34.375=2-34.375

    7x=-32.375

    7x/7=-32.375/7

    x=-4.625


    don't forget to look for the negatives the symbol is sometimes hard to see it is this little dash -

    oh by the way if ya think i did well give me a thumbs up
     
    Last edited: Sep 11, 2007
    #35
  36. Court_Jester

    Court_Jester Hall of Fame

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    I was about to post that your x value should have been negative but it seems that you were able to edit it.

    Good job! See how easy it is? :D

    Two thumbs up!
     
    #36
  37. bluestreak711

    bluestreak711 Rookie

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    thanks yea i did it right on paper but when i type it to the pc i always mistype something

    i most of the time and get in a hurry and type oyu instead of you

    but i'll be back for sure so stay subscribed to this thread please
     
    #37
  38. J-man

    J-man Hall of Fame

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    LOL that would be nice.
     
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  39. Duzza

    Duzza Legend

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    Come on...I don't do complex numbers.....anymore.

    Thanks for popping my expanding head though :D.
     
    #39
  40. dave333

    dave333 Hall of Fame

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    yes, we haved dived into the world of derivitives, limits, and other stuff...

    as for geometry, yeah, i hated geometry. So I skipped it. So happy i did it, cause we had to do formal proofs.

    I took algebra II and either got sleep or did my homework while my teacher blabbed on.

    I skipped pre-cal cuz my parents told me to.
     
    #40
  41. HellBunni

    HellBunni Rookie

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    lol, I was confused by what you were trying to ask. Never really seen it mentioned as Two missing factors, plus the reference to brackets didn't help.
     
    #41
  42. jasoncho92

    jasoncho92 Professional

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    Ive never heard of a school that just let you skip math courses just because you want to lol. And alg 1 was incredibly easy lol. I literally slept through most classes because i had it first period and i aced it easily lol. But what ap cal are you taking? AB or BC?
     
    #42
  43. bluestreak711

    bluestreak711 Rookie

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    ok need help again

    1/2x+1/3y=2
    x-1/3y=1

    :confused:
     
    #43
  44. bluestreak711

    bluestreak711 Rookie

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    and another one

    x-3y=7
    2x-2y=18
     
    #44
  45. HellBunni

    HellBunni Rookie

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    add the 2 equations together

    1/2x + 1/3y = 2
    1x - 1/3y = 1
    -----------------
    (1/2+1)x + (1/3 - 1/3)y = 2+1
    1.5 x = 3
    x = 2
     
    #45
  46. HellBunni

    HellBunni Rookie

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    either do substitution
    x - 3y = 7 => x = 7 + 3y
    so 2x - 2y = 18 => 2(7+3y) - 2y = 18

    or multiple first equation by -2
    -2*(x - 3y = 7) => -2x + 6y = - 14
    then add the two equations together
    -2x + 6y = -14
    2x - 2y = 18
    ----------------
    (-2 + 2)x + (6 - 2)y = -14 + 18
     
    #46
  47. bluestreak711

    bluestreak711 Rookie

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    i didnt get a bit of that
     
    #47
  48. HellBunni

    HellBunni Rookie

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    which didn't you get?
     
    #48
  49. bluestreak711

    bluestreak711 Rookie

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    both of them

    i was taught to find common factors in the equations then subtract

    then solve for a variable then plug it in to the first equation the gon on and solve for the last variable
     
    #49
  50. bluestreak711

    bluestreak711 Rookie

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    it might sound like i know what i am talking about but i half do and half dont


    im lost
     
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