document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1018559>Question 1018559</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a+b=20<BR>\n" );
document.write( "5a+9b=120<BR>\n" );
document.write( "solve for b </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #634631 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=634631\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Can do this by substitution or elimination.  Let me substitute.  a+b=20, a=20-b<BR>\n" );
document.write( "5(20-b)+9b=120<BR>\n" );
document.write( "100-5b+9b=120<BR>\n" );
document.write( "4b=20<BR>\n" );
document.write( "b=5<BR>\n" );
document.write( "a=15<BR>\n" );
document.write( "--------------<BR>\n" );
document.write( "check in second equation<BR>\n" );
document.write( "5(15)+9(5)=120, and that checks. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );