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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- Jul 19th 2006, 08:21 PMkwtolleyFind 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. - Jul 19th 2006, 08:48 PMCaptainBlackQuote:

Originally Posted by**kwtolley**

A=

\left[ \begin{array}{cc}

{5}& {1}\\

{3}& {2}

\end{array} \right],\ B=

\left[ \begin{array}{cc}

{-1}& {3}\\

{4}& {1}

\end{array} \right].

$

so:

$\displaystyle

A-2B=

\left[ \begin{array}{cc}

{5}& {1}\\

{3}& {2}

\end{array} \right]-

2 \times

\left[ \begin{array}{cc}

{-1}& {3}\\

{4}& {1}

\end{array} \right]

$

$\displaystyle

=

\left[ \begin{array}{cc}

{5}& {1}\\

{3}& {2}

\end{array} \right]-

\left[ \begin{array}{cc}

{-2}& {6}\\

{8}& {2}

\end{array} \right]=

\left[ \begin{array}{cc}

{7}& {-5}\\

{-5}& {0}

\end{array} \right]

$ - Jul 20th 2006, 12:35 AMkwtolleythanks
I thought mt answer was wrong. thanks again