document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=977943>Question 977943</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The sum of the digits of a certain two-digit number is 8. Reversing its digits decreases the number by 36. What is the number?\r<BR>\n" );
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document.write( "A plane traveled 720 miles to Tokyo and back. The trip there was with the wind. It took 6 hours. The trip back was into the wind. The trip back took 12 hours. Find the speed of the plane in still air and the speed of the wind. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #599448 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=599448\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> x is the tens digit<BR>\n" );
document.write( "y is the ones digit\r<BR>\n" );
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document.write( "10x+y is the number and 10y+x is the reverse\r<BR>\n" );
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document.write( "10x+y-36=10y+x<BR>\n" );
document.write( "9x-36=9y<BR>\n" );
document.write( "9x=9y+36<BR>\n" );
document.write( "x=y+4\r<BR>\n" );
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document.write( "x+y=8<BR>\n" );
document.write( "y+4+y=8 by substitution<BR>\n" );
document.write( "2y=4<BR>\n" );
document.write( "y=2<BR>\n" );
document.write( "x=6\r<BR>\n" );
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document.write( "62-36=26<BR>\n" );
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document.write( "120 mph average on the way there, which is x+y<BR>\n" );
document.write( "60 mph average on the way back, which is x-y<BR>\n" );
document.write( "x+y=120<BR>\n" );
document.write( "x-y=60<BR>\n" );
document.write( "2x=180<BR>\n" );
document.write( "x=90 mph of plane in still air<BR>\n" );
document.write( "y=30 mph of wind\r<BR>\n" );
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