document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1004790>Question 1004790</A>: <I><SPAN STYLE=\"word-break: break-all;\"> What is the units digits of 13^1972? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #621146 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=621146\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If you do the first five powers, you will see that the units digits cycles...<BR>\n" );
document.write( "13<BR>\n" );
document.write( "169<BR>\n" );
document.write( "2187<BR>\n" );
document.write( "ends in 1<BR>\n" );
document.write( "ends in 3<BR>\n" );
document.write( "etc...every four powers, it ends in 3,9,7,1...<BR>\n" );
document.write( "since 1972 is divisible by four evenly, 13^1972 must end in a 1. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );