document.write( "Question 292657: Multiplying matrics\r
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Algebra.Com's Answer #211361 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "This is a \"red%281%29\"\"x\"\"green%284%29\" matrix multiplied by a \"green%284%29\"\"x\"\"red%283%29\".\r
\n" ); document.write( "\n" ); document.write( "The multiplication is defined because the two (green) inner
\n" ); document.write( "dimensions are both \"green%284%29\" and the product matrix will
\n" ); document.write( "have the outer (red) dimensions \"red%281%29\"\"x\"\"red%283%29\". \r
\n" ); document.write( "\n" ); document.write( "So we make a blank \"1\"\"x\"\"3\" matrix to fill in:\r
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\n" ); document.write( "\n" ); document.write( "The first element to fill in is the 1st (only) row and 1st column.\r
\n" ); document.write( "\n" ); document.write( "So we multiply the first (only) row of the first matrix by the
\n" ); document.write( "first column of the second matrix and then add them like this:\r
\n" ); document.write( "\n" ); document.write( "\"4%2A1+%2B+1%2A2+%2B+0%2A3+%2B+2%2A1+=+4+%2B+2+%2B+0+%2B+2+=+8\", so
\n" ); document.write( "we put \"red%288%29\" in the first blank of the product matrix:\r
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\n" ); document.write( "\n" ); document.write( "The second element to fill in is the 1st (only) row and 2nd column.\r
\n" ); document.write( "\n" ); document.write( "So we multiply the first (only) row of the first matrix by the
\n" ); document.write( "2nd column of the second matrix and then add them like this:\r
\n" ); document.write( "\n" ); document.write( "\"4%2A0+%2B+1%2A%28-1%29+%2B+0%2A5+%2B+2%2A3+=+0+-+1+%2B+0+%2B+6+=+5\", so
\n" ); document.write( "we put \"red%285%29\" in the second blank of the product matrix:\r
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\n" ); document.write( "The third element to fill in is the 1st (only) row and 3rd column.\r
\n" ); document.write( "\n" ); document.write( "So we multiply the first (only) row of the first matrix by the
\n" ); document.write( "3rd column of the second matrix and then add them like this:\r
\n" ); document.write( "\n" ); document.write( "\"4%2A1+%2B+1%2A0+%2B+0%2A1+%2B+2%2A0+=+4+%2B+0+%2B+0+%2B+0+=+4\", so
\n" ); document.write( "we put \"red%284%29\" in the third blank of the product matrix:\r
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