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Math Help - finding roots

  1. #1
    Senior Member
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    finding roots

    how come I get different roots for
    -5t^2 +25t -30 ?
    by factorizing I get t=1 or t=-6
    by -b formula I get t=2 or t=3?
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  2. #2
    Grand Panjandrum
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    Quote Originally Posted by wolfhound View Post
    how come I get different roots for
    -5t^2 +25t -30 ?
    by factorizing I get t=1 or t=-6
    by -b formula I get t=2 or t=3?
    The formula roots are correct, the other roots are wrong, and if you don't tell us how you arrived at them we cannot tell you why.

    (and you could have checked these yourself by substituting them back into the equation)

    CB
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  3. #3
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    Quote Originally Posted by CaptainBlack View Post
    The formula roots are correct, the other roots are wrong, and if you don't tell us how you arrived at them we cannot tell you why.

    (and you could have checked these yourself by substituting them back into the equation)

    CB
    I know now..I took 5 out as a common factor and then left -t^2 as a + t^2 instead of - resulting in wrong factoring thanks!
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