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-   -   N2+4n-12=0 algebra 1b (https://www.askmehelpdesk.com/showthread.php?t=420134)

  • Nov 28, 2009, 04:13 PM
    shybaby
    n2+4n-12=0 algebra 1b
    n2+4n-12=0
  • Nov 28, 2009, 04:44 PM
    medic-dan

    Homework question?

    Get rid of the -12 side by adding 12 to both sides.

    n2+4n-12+12= 0+12

    n2+4n = 12

    Now can you solve it?
  • Nov 28, 2009, 04:57 PM
    mathwiz3502

    This will help you for any of these problems
    n^2+4n-12=0
    factor
    (n-2)(n+6)=0
    now since these are multiplied the zero property of multiplication says that at least one of these must equal 0
    so you get
    n-2=0
    and
    n+6=0
    solve them and you get
    n=2 and -6
    for proof
    2^2+2(4)-12=0
    4+8-12=0
    0=0
    (-6)^2+-6(4)-12=0
    36+-24-12=0
    0=0
    give me feedback
  • Nov 28, 2009, 08:53 PM
    medic-dan

    I thank you mathwizard. It's been a while but now that you post that I'm thinking FOIL again.
  • Nov 28, 2009, 11:58 PM
    morgaine300

    Quite frankly, I don't see the point of all that. Subtract the constant, combine like terms, divide, you're done.

    Of course, OP didn't say what the instructions actually were, but without seeing otherwise, I assume solving for n.
  • Nov 29, 2009, 05:20 AM
    mathwiz3502

    morgaine, many people coud not solve
    n^2+4n=12 because they would not think of negative 6, and since I'm actually taking the same course, no joke in acc. int. advanced math 1 and some off 2, so I know there will soon be harder equations which is why I tell him the "long 100% way."
  • Dec 1, 2009, 08:01 AM
    Unknown008

    There's another method, that however is a little more complex. It's called completing the square. Demonstration:















    So, n = -4 - 2 = -6 or
    n = 4 - 2 = 2

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