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mom
2013-05-29 03:46:15

Bob,

thanks so much.

bob bundy
2013-05-29 03:32:12

Yes; in matrix work AB means A multiplied by B.

Bob

mom
2013-05-29 03:31:03

Bob,

yes they are two 3 x 3 matrices. So for the second row of AB it would be [15 1 2] ?

It didn't say to multiply so I wasn't sure that I worked the problem correctly but if you have A matrix B matrix and you have to come up with the second row of AB for the matrices, was I correct in assuming that I was to multiply?

Thanks so much.

mom
2013-05-29 03:26:34

Please see attached. I have never uploaded in here before but the attachment shows how I did my work.

I know how to go through the process of multiplication for the matrices. I am just not sure that is what the question was asking me to do.

bob bundy
2013-05-29 03:24:35

hi mom,

That's correct.

{7/3} :  I think those are two 3 x 3 matrices.

Bob

{7/3}
2013-05-29 03:07:24

I'm confused,how can 1 by 3 and 1 by 3 matrices be multiplied?

mom
2013-05-29 02:37:39

I have:
Let A=[-2 1 3] and B = [0 1 -3]. Find the second row of AB.
1 0 5                1 3 -4
0 4 2                3 0  1

I multiplied and for the second row of AB, I got [15 1 2]

Is this correct?