document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=776837>Question 776837</A>: <I><SPAN STYLE=\"word-break: break-all;\"> THE FIFTH TERM OF AN ARITHEMETIC SEQUENCE IS 10 & THE SUM OF THE THE FIRST 10 TERMS IS 115. FIND IT'S FIRST TERM AND IT'S COMMON DIFFERENCE. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #473742 by </B><A HREF=/tutors/aboutme.mpl?userid=pakhi><B>pakhi(24)</B></A><img src=\"/images/stars/stars-07.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=pakhi><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=pakhi><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=473742\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let the 1st term be 'a' and the common difference be 'b'.<BR>\n" );
document.write( "Therefore the 5th term is a+4b = 10(given)----------------(1)<BR>\n" );
document.write( "The formula for the sum of 15 terms of an A.P. is<BR>\n" );
document.write( "     S(10)= (10/2)(2a+9b)=115 <BR>\n" );
document.write( "  or S(10)= 5(2a+9b)=115 <BR>\n" );
document.write( "  or S(10)= 10a+45b =115 ----------------------------------(2)<BR>\n" );
document.write( "  <BR>\n" );
document.write( "Multiplying equation1 by 10 we have 10a+40b = 100 --------(3)<BR>\n" );
document.write( "Subtracting equation3 from equation2 we have 5b= 15<BR>\n" );
document.write( "So we have b=3(common difference)\r<BR>\n" );
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document.write( "Putting the value of 'b' in equation1 we have a+4*3=10<BR>\n" );
document.write( "So a=10-12= -2(first term of the series)<BR>\n" );
document.write( " </SPAN>\n" );
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