document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1046047>Question 1046047</A>: <I><SPAN STYLE=\"word-break: break-all;\"> nP4=84nC2 Solve for n using factorial notation\r<BR>\n" );
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document.write( "I'm really struggling with this question and would be grateful for help, please and thank you.\r<BR>\n" );
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document.write( "This is what I've tried but it feels really messy and wrong.\r<BR>\n" );
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document.write( "n(n-1)(n-2)(n-3)(n-4)!/(n-4)! = 84 {n(n-1)(n-2)!/2!(n-2)!}<BR>\n" );
document.write( "n(n-1)(n-2)(n-3) = 84 {n(n-1)/2}<BR>\n" );
document.write( "2{n(n-1)(n-2)(n-3)} = 84{n(n-1)/2) x2/1}<BR>\n" );
document.write( "2{n(n-1)(n-2)(n-3)}/n(n-1) = 84{n(n-1)}/n(n-1)<BR>\n" );
document.write( "2{(n-2)(n-3)}/2 = 84/2<BR>\n" );
document.write( "(n-2)(n-3) = 42<BR>\n" );
document.write( "n^2-5n-36=0<BR>\n" );
document.write( "(n-9)(n+4)=0<BR>\n" );
document.write( "n=9 because n cannot be negative (-4)<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #661546 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52847)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ikleyn><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=ikleyn><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=661546\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .<BR>\n" );
document.write( "nP4=84nC2 Solve for n using factorial notation\r<BR>\n" );
document.write( "\n" );
document.write( "I'm really struggling with this question and would be grateful for help, please and thank you.\r<BR>\n" );
document.write( "\n" );
document.write( "This is what I've tried but it feels really messy and wrong.\r<BR>\n" );
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document.write( "<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( "n(n-1)(n-2)(n-3)(n-4)!/(n-4)! = 84 {n(n-1)(n-2)!/2!(n-2)!}    - This line is wrong.    Take it off.\r\n" );
document.write( "n(n-1)(n-2)(n-3) = 84 {n(n-1)/2}                              - This line is correct.  Keep it.\r\n" );
document.write( "2{n(n-1)(n-2)(n-3)} = 84{n(n-1)/2) x2/1}                      - This line is wrong.    Take it off.\r\n" );
document.write( "2{n(n-1)(n-2)(n-3)}/n(n-1) = 84{n(n-1)}/n(n-1)                - This line is wrong.    Take it off.\r\n" );
document.write( "2{(n-2)(n-3)}/2 = 84/2                                        - This line is correct.  Keep it.\r\n" );
document.write( "(n-2)(n-3) = 42                                               - This line is correct.  Keep it.\r\n" );
document.write( "n^2-5n-36=0                                                   - This line is correct.  Keep it.\r\n" );
document.write( "(n-9)(n+4)=0                                                  - This line is correct.  Keep it.\r\n" );
document.write( "n=9 because n cannot be negative (-4)                         - This line is correct.  Keep it.\r\n" );
document.write( "</PRE>\r<BR>\n" );
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document.write( "Now I really take off the incorrect lines and keep only the correct ones.\r<BR>\n" );
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document.write( "<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( "nP4=84nC2 Solve for n using factorial notation\r\n" );
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document.write( "n(n-1)(n-2)(n-3) = 84 {n(n-1)/2}\r\n" );
document.write( "2{n(n-1)(n-2)(n-3)}/(n(n-1)) = 84{n(n-1)}/(n(n-1))\r\n" );
document.write( "2{(n-2)(n-3)}/2 = 84/2\r\n" );
document.write( "(n-2)(n-3) = 42\r\n" );
document.write( "n^2-5n-36=0\r\n" );
document.write( "(n-9)(n+4)=0\r\n" );
document.write( "n=9 because n cannot be negative (-4)\r\n" );
document.write( "</PRE>\r<BR>\n" );
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document.write( "Now you have the correct solution.\r<BR>\n" );
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