Evening Reading

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• 14s . : rheroux
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  8 and 20 : mechanicalgrape
  • :( : GloriousCow
• 20 and 8 : GloriousCow
• hamburger : spectr3
• 20 and 8 : trove
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  x + y = 28 x = 28 - y x * y = 160 (28 - y) * y = 160 y^2 - 28y + 160 = 0 (y - 20) * (y - 8) = 0 ... : Ecks
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    Fuck, I was going that way, decided to just brute force it. My mathfu sucks. : trove
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      Brute force? You mean you guessed? : ieGod
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        I guess you could describe it as such. : trove
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          Would Eck's approach work for really large numbers (that would take considerably longer to factor)? : Maddog_Delphi97
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            factoring a quadratic never takes a long time, it's pretty simple : veras
            • It's been a while since I factored a quadratic, so I'm a little rusty in this area. : Maddog_Delphi97
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            "Ecks way" is silly. It just adds fluff around the real meat, which is factoring the line "y^2 - 28y +160... : CtrlFrk
            • Silly? There's no fluff about it - that's the formal way to arrive at the full quadratic, regardless of a... : ieGod
    • ayo, lesson here. you come at the king, you best not miss. : liquidlies
  • Sever : VegasX
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    question. How do you get from the second last line to the last line without figuring out the answer to... : hanabal
    • one of the two parenthesis needs to equal 0 to balance the equation. : shirif
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      (y - 20) * (y - 8) = 0 Divide both sides by (y - 8): ((y - 20) * (y - 8)) / (y - 8) = 0 / (y - 8) Res... : JarEme
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        I tihnk he was asking how to factor : boring gegtik
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          Nuts to typing that out. : JarEme
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            There we go: http://shackpics.com/viewer.x?file=factoring_w3df3uuo9wfp4jvbr5j5.jpg From ax² + bx + ... : JarEme
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              Who else sees the mistake I made? : JarEme
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                Yep, you left the root sign over the 12 : CtrlFrk
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                  That and the minus symbol missing after B on the third to last line (left column) : shirif
                  • Yeah that's probably a bigger mistake because it actually affected his answer >.> : CtrlFrk
                  • cheers Its been so long I completely forgot about the quadratic equation. I really need to brush up on my... : hanabal
              • you wrote on what appear to be toilet paper : the_burd
    • there's various ways to factor it, if you're bad at intuitive factoring you can always fall back on http:... : veras
    • reverse FOIL : DonkeyPopsicle
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  Beat his ass until he tells you the numbers : jingletard
  • give him a pack of newports : Yanks
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  Omar comin! OMAR! : Matt Burris
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    That's what I was thinking, why would he want to know this? ;D : DM7
    • trying to divide the stash : alexpr
• .45 and he always keeps a round in the chamber in case you're pondering. : roushimsx
• http://www.wolframalpha.com/input/?i=+x%2By%3D28+and+x*y%3D160 : angrytaxman
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  How tall is Imhotep? : dirge23
  • Imhotep is invisible. : Blamco Mac & Cheese
• #742

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  By: multisync x Show Full Post

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  i'm pretty sure 'Omar' wouldn't be able to do such math in his head

  Jan 18, 2011 6:44pm PST
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  i'm pretty sure 'Omar' wouldn't be able to do such math in his head : multisync
  • Indeed : VivaMachete
  • technically the only thing omar is doing is thinking of two numbers thats all hes doing. the sum and prod... : spiderfill
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  This is the same as asking how to factor x^2 - 28x +160, if you want to do it methodically, you can break... : CtrlFrk
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    wtf is all this? look at 160, look at 28. it's simple : theylookwolfs
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      Okay, now do it for a*b = 198296436 and a+b = 60740. Simple. : CtrlFrk
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        3462 and 57278 : Maddog_Delphi97
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          http://pastebin.com/WtnadVuT : Maddog_Delphi97
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            Ah, you used all the factors, rather than just finding combinations of the prime factors. ( Prime fac... : CtrlFrk
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              Oh I just assumed you were looking for two numbers, since you said a and b. : Maddog_Delphi97
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                I was! And your answer is correct, but your program used a different method to the one i showed. : CtrlFrk
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                  Oh ok. lol I should write a version that factors numbers as well. : Maddog_Delphi97
                  • Especially if I want to find prime factors, yeah. :D : Maddog_Delphi97
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                    I tried one that built a list of primes as it goes: http://jsfiddle.net/ctrlfrk/zEpR8/5/ It's pretty hor... : CtrlFrk
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                      Math majors will have a field day with this, since they know all kinds of cute math tricks, like using th... : Maddog_Delphi97
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                        You can just use the quadratic formula as well to solve this for any product/sum pair. : jim bone
                        • It's the cutest of all math tricks. : jim bone
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                        http://dotnetperls.com/prime This looks like a good approach to finding prime numbers. : Maddog_Delphi97
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                          Prime factorization has extremely poor complexity so you're probably better of factoring the quadratic us... : jim bone
                          • Oh. : Maddog_Delphi97
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    This is interesting and confusing. I think I will stick to traditional methods of factoring. : jim bone
    • Agreed. I wrote a quick F# implementation of this logic ( http://pastebin.com/AzgEzFw3 ) to wrap my head ... : Satyric0n
  • Is this some kind of New Math witchcraft? : JarEme
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  14? : spaceless
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    lol joke : spaceless
    • Suuuure! : Edges
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  who gives a fuck : CoRDS
  • All of North Carolina, did you not scroll through this thread? : dognose
• 4, and -8 : HL3dsx