document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=985683>Question 985683</A>: <I><SPAN STYLE=\"word-break: break-all;\"> This is the second part of my first question:<BR>\n" );
document.write( "(I put multiple periods in between the letters and numbers so that the matrices would be whole.)\r<BR>\n" );
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document.write( "Given matrices: <BR>\n" );
document.write( "A: [3] \r<BR>\n" );
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document.write( "B:[2 9] \r<BR>\n" );
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document.write( "C: [2 4 -3<BR>\n" );
document.write( "....-2 3 0] \r<BR>\n" );
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document.write( "D: [ 3 2<BR>\n" );
document.write( "......3 2<BR>\n" );
document.write( "......3 2] \r<BR>\n" );
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document.write( "E: [-8 -2<BR>\n" );
document.write( "......0 0] \r<BR>\n" );
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document.write( "F: [ 2 3 4 5 6 7 9] \r<BR>\n" );
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document.write( "G: <BR>\n" );
document.write( "[3<BR>\n" );
document.write( "2<BR>\n" );
document.write( "1<BR>\n" );
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document.write( "9<BR>\n" );
document.write( "8<BR>\n" );
document.write( "7] \r<BR>\n" );
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document.write( "Which matrices can be multiplied by A on the right?<BR>\n" );
document.write( "(Enter the uppercase letters corresponding  to the correct answer.)\r<BR>\n" );
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document.write( "Thank you. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #606504 by </B><A HREF=/tutors/aboutme.mpl?userid=Edwin+McCravy><B>Edwin McCravy(20055)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Edwin+McCravy><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Edwin+McCravy><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=606504\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <PRE STYLE=\"white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;\">\r\n" );
document.write( "The dimensions of a matrrix is \"down by across\"\r\n" );
document.write( "That is, you count how many numbers there are counting downward from\r\n" );
document.write( "top to bottom.  That's the \"down\" dimension.  Then you count how many\r\n" );
document.write( "number there are going from left to right.  That the \"across\" number.\r\n" );
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document.write( "In order for a matrix on the left to be multiplied by a matrix on\r\n" );
document.write( "the right, the ACROSS number of the matrix on the left must be the\r\n" );
document.write( "same as the DOWN number on the right. \r\n" );
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document.write( "This is the second part of my first question:\r\n" );
document.write( "(I put multiple periods in between the letters and numbers so that the matrices would be whole.)\r\n" );
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document.write( "Let's find the dimensions of all the given matrices: \r\n" );
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document.write( "A: [3]   That's 1 down and 1 across, so it's a 1x1 matrix \r\n" );
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document.write( "B:[2 9]   That's 1 down and 2 across, so it's a 1x2 matrix \r\n" );
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document.write( "C: [2 4 -3    That's 2 down and 3 across, so it's a 2x3 matrix \r\n" );
document.write( "   -2 3 0] \r\n" );
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document.write( "D:   [3 2    That's 3 down and 2 across, so it's a 3x2 matrix     \r\n" );
document.write( "      3 2\r\n" );
document.write( "      3 2] \r\n" );
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document.write( "E:  [-8 -2   That's 2 down and 2 across, so it's a 2x2 matrix \r\n" );
document.write( "      0 0] \r\n" );
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document.write( "F: [ 2 3 4 5 6 7 9] That's 1 down and 9 across, so it's a 1x9 matrix  \r\n" );
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document.write( "G: \r\n" );
document.write( "    [3\r\n" );
document.write( "     2\r\n" );
document.write( "     1\r\n" );
document.write( "     0\r\n" );
document.write( "     9\r\n" );
document.write( "     8\r\n" );
document.write( "     7]  That's 7 down and 1 across, so it's a 7x1 matrix \r\n" );
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document.write( "Which matrices can be multiplied by A on the right?\r\n" );
document.write( "(Enter the uppercase letters corresponding  to the correct answer.)\r\n" );
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document.write( "The ACROSS number of A is 1, so any matrix that can multiply by A on\r\n" );
document.write( "the right must have a DOWN number of 1.  Only A, B and F have DOWN numbers\r\n" );
document.write( "of 1. \r\n" );
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document.write( "Now be sure you understand why those are the correct answers.  Don't just enter\r\n" );
document.write( "them in the computer and forget it.\r\n" );
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document.write( "Edwin</PRE> </SPAN>\n" );
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