document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1045421>Question 1045421</A>: <I><SPAN STYLE=\"word-break: break-all;\"> ncr +2×ncr-1+ncr-2 =n+2cr </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #660912 by </B><A HREF=/tutors/aboutme.mpl?userid=robertb><B>robertb(5830)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=robertb><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=robertb><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=660912\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> To prove: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28matrix%282%2C1%2Cn%2Cr%29%29%2B2%2A%28matrix%282%2C1%2Cn%2Cr-1%29%29+%2B+%28matrix%282%2C1%2Cn%2Cr-2%29%29+=+%28matrix%282%2C1%2Cn%2B2%2Cr%29%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "We make use of the Pascal's Triangle:  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28matrix%282%2C1%2Cn%2Cr%29%29+%2B+%28matrix%282%2C1%2Cn%2Cr-1%29%29+=+%28matrix%282%2C1%2Cn%2B1%2Cr%29%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "===> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28matrix%282%2C1%2Cn%2Cr%29%29%2B2%2A%28matrix%282%2C1%2Cn%2Cr-1%29%29+%2B+%28matrix%282%2C1%2Cn%2Cr-2%29%29+ ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "= <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28matrix%282%2C1%2Cn%2Cr%29%29+%2B+%28matrix%282%2C1%2Cn%2Cr-1%29%29+%2B+%28matrix%282%2C1%2Cn%2Cr-1%29%29+%2B%28matrix%282%2C1%2Cn%2Cr-2%29%29+ ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "=<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%28matrix%282%2C1%2Cn%2Cr%29%29+%2B+%28matrix%282%2C1%2Cn%2Cr-1%29%29%29+%2B+%28%28matrix%282%2C1%2Cn%2Cr-1%29%29+%2B%28matrix%282%2C1%2Cn%2Cr-2%29%29%29+ ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "= <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28matrix%282%2C1%2Cn%2B1%2Cr%29%29+%2B+%28matrix%282%2C1%2Cn%2B1%2Cr-1%29%29 ALIGN=MIDDLE  ALT=\"%28matrix%282%2C1%2Cn%2B1%2Cr%29%29+%2B+%28matrix%282%2C1%2Cn%2B1%2Cr-1%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, <BR>\n" );
document.write( "= <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28matrix%282%2C1%2Cn%2B2%2Cr%29%29 ALIGN=MIDDLE  ALT=\"%28matrix%282%2C1%2Cn%2B2%2Cr%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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