document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1144092>Question 1144092</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The sum of the digits of a two-digit number is 7. The tens' digit is one more than twice the units' digit. Find the number. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #765080 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13200)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=765080\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "If you just need an answer, look at pairs of digits whose sum is 7 and find the pair for which one of them is 2 more than two times the other.<br><BR>\n" );
document.write( "If you are supposed to solve the problem as an exercise in algebra, then you have two basic options.<br><BR>\n" );
document.write( "(1) Using two variables....<br><BR>\n" );
document.write( "let t = tens digit<BR>\n" );
document.write( "let u = units digit<br><BR>\n" );
document.write( "Then<br><BR>\n" );
document.write( "t+u = 7 (the sum of the two digits is 7)<BR>\n" );
document.write( "t = 2u+1 (the tens digit is 1 more than twice the units digit)<br><BR>\n" );
document.write( "Solve the pair of equations by any method you want.  Substitution looks appropriate.<br><BR>\n" );
document.write( "(2) Using a single variable....<br><BR>\n" );
document.write( "let t = tens digit<BR>\n" );
document.write( "then 7-t = units digit  (because you are given t+u=7)<br><BR>\n" );
document.write( "Then<br><BR>\n" );
document.write( "t = 2(7-t)+1 (the tens digit is 1 more than twice the units digit)<br><BR>\n" );
document.write( "Solve using basic algebra. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );