document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=380925>Question 380925</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Is this closed under addition? \r<BR>\n" );
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document.write( "{7,14,21,28,...}\r<BR>\n" );
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document.write( "Margarita </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #270303 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=270303\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Yes because every number is in the form 7n where n is a positive integer\r<BR>\n" );
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document.write( "So take two numbers say 7n and 7m and add them to get 7n+7m=7(n+m) which is a multiple of 7, which means that this set is closed under addition. </SPAN>\n" );
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