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Math Help - Find A-2B

  1. #1
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    Question Find A-2B

    A= 5 1 B= -1 3
    3 2 4 1 Find A-2B
    My answer is -1 3
    4 1 I don't think this is right after using excel, thanks for checking.
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  2. #2
    Grand Panjandrum
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    Quote Originally Posted by kwtolley
    A= 5 1 B= -1 3
    3 2 4 1 Find A-2B
    My answer is -1 3
    4 1 I don't think this is right after using excel, thanks for checking.
    <br />
A=<br />
\left[ \begin{array}{cc}<br />
{5}& {1}\\<br />
{3}& {2}<br />
\end{array} \right],\ B=<br />
\left[ \begin{array}{cc}<br />
{-1}& {3}\\<br />
{4}& {1}<br />
\end{array} \right].<br />

    so:

    <br />
A-2B=<br />
\left[ \begin{array}{cc}<br />
{5}& {1}\\<br />
{3}& {2}<br />
\end{array} \right]-<br />
2 \times <br />
\left[ \begin{array}{cc}<br />
{-1}& {3}\\<br />
{4}& {1}<br />
\end{array} \right]<br />


    <br />
=<br />
\left[ \begin{array}{cc}<br />
{5}& {1}\\<br />
{3}& {2}<br />
\end{array} \right]-<br />
\left[ \begin{array}{cc}<br />
{-2}& {6}\\<br />
{8}& {2}<br />
\end{array} \right]=<br />
\left[ \begin{array}{cc}<br />
{7}& {-5}\\<br />
{-5}& {0}<br />
\end{array} \right]<br />
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  3. #3
    Member
    Joined
    Jun 2006
    Posts
    165

    Smile thanks

    I thought mt answer was wrong. thanks again
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