document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=134757>Question 134757</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0028242270/algebrahomeworkh>merrill algebra 2 with trigonometry applications and connections</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> i cant figure out these problems<BR>\n" );
document.write( "27.  75 sigma n=21 (2n+5) i solved this problem using the formula Sn=n/2(a1+an) and i got 5454 when the answer in the back was 5555.  what did i do wrong\r<BR>\n" );
document.write( "\n" );
document.write( "31.  d=5, n=16, an=72 find Sn for the sequence<BR>\n" );
document.write( "how do you get a1<BR>\n" );
document.write( "help me solve these plese </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #98598 by </B><A HREF=/tutors/aboutme.mpl?userid=vleith><B>vleith(2983)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=vleith><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=98598\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Don't know on the first one,\r<BR>\n" );
document.write( "\n" );
document.write( "but to get the a1 in the second one 72 = a1 + (n-1)d </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );