document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=62883>Question 62883</A>: <I><SPAN STYLE=\"word-break: break-all;\"> okay, i'm not very good at matrices...\r<BR>\n" );
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document.write( "[4 2]____[-6   0]<BR>\n" );
document.write( "[5 1]*A= [-15  3]\r<BR>\n" );
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document.write( "(find matrix A)<BR>\n" );
document.write( "please help i'll be very grateful!!\r<BR>\n" );
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document.write( "ps. sorry if it's confusing these are two 2x2 matrices ^^ </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #43708 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=43708\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> [4 2]____[-6   0]<BR>\n" );
document.write( "[5 1]*A= [-15  3]<BR>\n" );
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document.write( "Assume A =[a b]<BR>\n" );
document.write( "..........[c d]<BR>\n" );
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document.write( "Multiplying the matrices you get 4 equations:<BR>\n" );
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document.write( "First Set of equations:<BR>\n" );
document.write( "1st: 4a+2c=-6<BR>\n" );
document.write( "2nd: 5a+c=-15<BR>\n" );
document.write( "Multiply 2nd by 2 to get:<BR>\n" );
document.write( "5th: 10a+2c=-30<BR>\n" );
document.write( "Subtract 1st from 5th to get:<BR>\n" );
document.write( "6a=-24<BR>\n" );
document.write( "a=-4<BR>\n" );
document.write( "Substitute into 2nd to solve for \"c\", as follows:<BR>\n" );
document.write( "5(-4)+c=-1<BR>\n" );
document.write( "c=19<BR>\n" );
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document.write( "Second set of equations:<BR>\n" );
document.write( "3rd: 4b+2d=0<BR>\n" );
document.write( "4th: 5b+d=3<BR>\n" );
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document.write( "Multiply 4th by 2 to get:<BR>\n" );
document.write( "6th: 10b+2d=6<BR>\n" );
document.write( "Subtract 3rd from 6th to get:<BR>\n" );
document.write( "6b=6<BR>\n" );
document.write( "b=1<BR>\n" );
document.write( "Substitute into 3rd to solve for \"d\":<BR>\n" );
document.write( "4(1)+2d=0<BR>\n" );
document.write( "d=-2<BR>\n" );
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document.write( "You now have a,b,c,d which are the elements of matrix A.<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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