document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1041057>Question 1041057</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find a1 if d = 4, a20 = 82, and S20 = 880. \r<BR>\n" );
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document.write( "A.) 2 <BR>\n" );
document.write( "B.) 4 <BR>\n" );
document.write( "C.) 6 <BR>\n" );
document.write( "D.) 60 \r<BR>\n" );
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document.write( "is this the right rule? <BR>\n" );
document.write( "an = a1+(n-1)d <BR>\n" );
document.write( "Sn = (n/2)(a1+an)\r<BR>\n" );
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document.write( "If so can I see a demonstration on how you solve it? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #655983 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=655983\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  Find a1 if d = 4, a20 = 82, and S20 = 880. <BR>\n" );
document.write( "A.) 2 <BR>\n" );
document.write( "B.) 4 <BR>\n" );
document.write( "C.) 6 <BR>\n" );
document.write( "D.) 60 <BR>\n" );
document.write( "----------------------<BR>\n" );
document.write( "an = a1+(n-1)d <BR>\n" );
document.write( "Sn = (n/2)(a1+an) <BR>\n" );
document.write( "----------<BR>\n" );
document.write( "a(20) = a(1) + 19*4 = a(1) + 76 = 82<BR>\n" );
document.write( "a(1) = 82-76 = 6<BR>\n" );
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document.write( "S(20) = (20/2)(a(1) + a(20)) = 10(a(1) + 82)) = 880<BR>\n" );
document.write( "a(1) + 82 = 88<BR>\n" );
document.write( "a(1) = 6<BR>\n" );
document.write( "----------------------<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "================== </SPAN>\n" );
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