document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=6806>Question 6806</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me solve the system of equations y = 2x - 10 and x - y = 7.\r<BR>\n" );
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document.write( "Thank you for the help in advance.\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #3746 by </B><A HREF=/tutors/aboutme.mpl?userid=glabow><B>glabow(165)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=glabow><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=3746\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The simplest way to solves these two equations simultaneously is to use substitution. <BR>\n" );
document.write( "y = 2x - 10<BR>\n" );
document.write( "x - y = 7\r<BR>\n" );
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document.write( "The second equation is rearranged to give the value of x:<BR>\n" );
document.write( "x = 7 + y [add y to both sides]<BR>\n" );
document.write( "Substituting the expression 7+y for x in the first equation gives<BR>\n" );
document.write( "y = 2(7+y) - 10<BR>\n" );
document.write( "which is<BR>\n" );
document.write( "y = 14 + 2y - 10 <BR>\n" );
document.write( "-y = 4 [subtract 2y from both sides]<BR>\n" );
document.write( "y = -4 [multiply both sides by -1]<BR>\n" );
document.write( "So, x = 7+y = 7+(-4) = 3.<BR>\n" );
document.write( "Checking,<BR>\n" );
document.write( "-4 = 6 - 10 [first equation]<BR>\n" );
document.write( "3 -(-4) = 7 [second equation]<BR>\n" );
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