document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=999570>Question 999570</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An auditorium has.7 seats in the first row. 11 seats in the second row.15 seats'  I n third row. How many seats in seventh row?<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #617202 by </B><A HREF=/tutors/aboutme.mpl?userid=fractalier><B>fractalier(6550)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=fractalier><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=fractalier><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=617202\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> You can see that each row has four more seats than the row in front of it, so<BR>\n" );
document.write( "7,11,15,19,23,27,31<BR>\n" );
document.write( "or<BR>\n" );
document.write( "a(7) = a(1) + (n-1)d<BR>\n" );
document.write( "a(7) = 7 + 6(4) = 31 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );