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Math Help - factorising

  1. #1
    Senior Member Mukilab's Avatar
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    factorising

    Factorise m^2+9m+20

    I thought it would be (m+10)(m-1) but that wouldn't work
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  2. #2
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    e^(i*pi)'s Avatar
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    Quote Originally Posted by Mukilab View Post
    Factorise m^2+9m+20

    I thought it would be (m+10)(m-1) but that wouldn't work
    Both your signs will be + since 9 and 20 are both greater than 0. Think about what other numbers multiply to make 20.

    20 =  1 \times 20 \: , 2 \times 10 , 4 \times 5

    From the above pick a pair that add up to 9

    The answer is (m+4)(m+5)
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  3. #3
    MHF Contributor alexmahone's Avatar
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    m^2+9m+20=(m+5)(m+4)
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  4. #4
    Senior Member Mukilab's Avatar
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    Lol I am such an idiot >.<
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