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Math Help - Help with just a few?

  1. #1
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    Help with just a few?

    I'm doing my homework and these are a few I need help with.

    1) a^2 - 416 = 0

    a= or a=

    2) (4+7i)(3+2i)

    3) (5i)^3

    4) (-5+5i) + (7-7i)
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  2. #2
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    Quote Originally Posted by knowledgekick View Post
    I'm doing my homework and these are a few I need help with.

    1) a^2 - 416 = 0

    \textcolor{red}{(a+\sqrt{416})(a-\sqrt{416}) = 0}

    for simplification purposes, note that \textcolor{red}{416 = 16 \cdot 26}

    2) (4+7i)(3+2i)

    multiply it out ... remember that \textcolor{red}{i^2 = -1}

    3) (5i)^3

    hint ... \textcolor{red}{i^3 = i^2 \cdot i}

    4) (-5+5i) + (7-7i)

    just combine like terms for this one
    ...
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