document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=203405>Question 203405</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Solve by the elimination method.<BR>\n" );
document.write( "7r+3s=38<BR>\n" );
document.write( "3r+7s=66<BR>\n" );
document.write( "--------------<BR>\n" );
document.write( "21r+9s =114<BR>\n" );
document.write( "21r-49= 462<BR>\n" );
document.write( "58/576<BR>\n" );
document.write( "S=? 9.9....?<BR>\n" );
document.write( "--------------<BR>\n" );
document.write( "7r-3(?)=?<BR>\n" );
document.write( "R=?<BR>\n" );
document.write( "It doesn’t make sense to me. Can you please help me solving this problem?<BR>\n" );
document.write( "Thank you!\r<BR>\n" );
document.write( "\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 #153467 by </B><A HREF=/tutors/aboutme.mpl?userid=jsmallt9><B>jsmallt9(3758)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jsmallt9><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=153467\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <PRE STYLE=\"white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;\">\r\n" );
document.write( "Solve by the elimination method.\r\n" );
document.write( "7r+3s=38\r\n" );
document.write( "3r+7s=66\r\n" );
document.write( "--------------\r\n" );
document.write( "21r+ 9s = 114\r\n" );
document.write( "21r+49s = 462\r\n" );
document.write( "</PRE><BR>\n" );
document.write( "Except for the \"-\" in front of the 49 and the missing \"s\" after the 49, you are good so far. Now we can subtract the second equation from the first one. As a result, the 21r terms will cancel which is the key to the Elimination Method. After subtracting we have:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-40s+=+-348 ALIGN=MIDDLE  ALT=\"-40s+=+-348\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Now we solve this equation. Divide by -40:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s+=+348%2F40+=+87%2F10 ALIGN=MIDDLE  ALT=\"s+=+348%2F40+=+87%2F10\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Now we substitute this value in for \"s\" into one of the original equations:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7r+%2B+3%2887%2F10%29+=+38 ALIGN=MIDDLE  ALT=\"7r+%2B+3%2887%2F10%29+=+38\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7r+%2B+261%2F10+=+38 ALIGN=MIDDLE  ALT=\"7r+%2B+261%2F10+=+38\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Multiply by 10 to eliminate the fraction:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=70r+%2B+261+=+380 ALIGN=MIDDLE  ALT=\"70r+%2B+261+=+380\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Subtract 261 from both sides:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=70r+=+119 ALIGN=MIDDLE  ALT=\"70r+=+119\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Divide by 70:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+119%2F70+=+17%2F10 ALIGN=MIDDLE  ALT=\"r+=+119%2F70+=+17%2F10\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "So the solution is<BR>\n" );
document.write( "r = 17/10 and s = 89/10<BR>\n" );
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document.write( "</TD></TR></TABLE>\n" );