document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1178050>Question 1178050</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The 6th term of an AP is 35 and the 13term is 77calculate S6-S4?\r<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 #807226 by </B><A HREF=/tutors/aboutme.mpl?userid=chhavi_1997><B>chhavi_1997(1)</B></A><img src=\"/images/stars/iconNewId_16x16.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=chhavi_1997><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=807226\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Given t6=35<BR>\n" );
document.write( "t13=77\r<BR>\n" );
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document.write( "therefore, t6= a+(n-1)d=a+(6-1)d<BR>\n" );
document.write( "35=a+5d .....1\r<BR>\n" );
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document.write( "t13= a+(13-1)d= a+12d<BR>\n" );
document.write( "77=a+12d ...2\r<BR>\n" );
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document.write( "by solving 1 and 2 we have<BR>\n" );
document.write( "a=5, d=6\r<BR>\n" );
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document.write( "now, sn=n/2(2a+(n-1)d) using this formula<BR>\n" );
document.write( "s6=6/2(2*5+(6-1)*6)<BR>\n" );
document.write( "s6=3(10+5*6)<BR>\n" );
document.write( "s6=120\r<BR>\n" );
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document.write( "similary,s4=4/2(2*5+(4-1)*6)<BR>\n" );
document.write( "s4=2(10+3*6)<BR>\n" );
document.write( "s4=56\r<BR>\n" );
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document.write( "therefore, s6-s4= 120-56<BR>\n" );
document.write( "s6-s4=64<BR>\n" );
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