document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=12425>Question 12425</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hello,\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "I would greatly appreciate it if a tutor could please verify my work for the below problem.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Find the determinant of the matrix B = [-1, 2, 3, 6, 0, 2, 3, 5, 1].  Matrix B is a 3x3 square matrix.  The first column is -1, 2, 3.  The second column is 6, 0, 2.  The third column in 3, 5, 1.  Row 1 is -1, 6, 3.  Row 2 is 2, 0 , 5.  Row 3 is 3, 2, 1.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "I started by taking the numbers of the first row (-1, 6, 3) and multiplying them by the 2x2 matrix that remains when the row and column each number is in is deleted.<BR>\n" );
document.write( "det B = -1[(0)(1)-(5)(2)] - 6[(2)(1)-(5)(3)] + 3[(2)(2)-(0)(3)]<BR>\n" );
document.write( "det B = -1(0-10) - 6(2-15) + 3(4 - 0)<BR>\n" );
document.write( "det B = -1(-10) - 6(-13) + 3(4)<BR>\n" );
document.write( "det B = 10 + 78 + 12<BR>\n" );
document.write( "det B = 100\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "In advance, thank you for your assistance!<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #6315 by </B><A HREF=/tutors/aboutme.mpl?userid=khwang><B>khwang(438)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=khwang><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=6315\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  B =<BR>\n" );
document.write( " [-1  6 3 ]<BR>\n" );
document.write( " [ 2  0 5]<BR>\n" );
document.write( " [ 3  2 1]<BR>\n" );
document.write( " You did a good job and the answer is correct.\r<BR>\n" );
document.write( "\n" );
document.write( " But, wy not expanding along the 2nd row ,since it contains 0.<BR>\n" );
document.write( " det(B) = -2(6-6) - 5(-2 -18) = 100\r<BR>\n" );
document.write( "\n" );
document.write( " Also,you typed too many redundant 0's and repetitive det(B) in<BR>\n" );
document.write( " your solution. Such as<BR>\n" );
document.write( " det B = -1(0-10) - 6(2-15) + 3(4 - 0) <BR>\n" );
document.write( " It seems that you don't have enough confdence in yourself.<BR>\n" );
document.write( " [Try to use your eyes and mind to calculate small numbers<BR>\n" );
document.write( " instead of using pen, or other tools.]<BR>\n" );
document.write( " <BR>\n" );
document.write( " I am a very lazy person,that is why I am always looking for the<BR>\n" );
document.write( " shortest cut to solve the problems.\r<BR>\n" );
document.write( "\n" );
document.write( " Kenny </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );