Find 3A-B when

A= 2 -1

3 0

B= 4 -2

5 1 my answer is 2 -1

4 1 is this right, thanks for checking and helping me also.

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- Jan 30th 2007, 11:45 PMkwtolleyMatrix help
Find 3A-B when

A= 2 -1

3 0

B= 4 -2

5 1 my answer is 2 -1

4 1 is this right, thanks for checking and helping me also. - Jan 31st 2007, 02:15 AMCaptainBlack

$\displaystyle A=\left( \begin{array}{cc} 2&-1 \\ 3&0 \end{array}\right) $

$\displaystyle B=\left( \begin{array}{cc} 4&-2 \\ 5&1 \end{array}\right) $

Then:

$\displaystyle

3A-B= 3 \left( \begin{array}{cc} 2&-1 \\ 3&0 \end{array}\right)-\left( \begin{array}{cc} 4&-2 \\ 5&1 \end{array}\right)

$$\displaystyle

=\left( \begin{array}{cc} 3\times 2-4&3\times(-1)+2 \\ 3 \times 3-5&3 \times 0-1 \end{array}\right)

$$\displaystyle

=$$\displaystyle

\left( \begin{array}{cc} 2&-1 \\ 4&-1 \end{array}\right)

$

RonL - Jan 31st 2007, 07:56 AMkwtolleythanks again
Thats what I had, but I liked the way you broke it down. thanks so much.