document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1015557>Question 1015557</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 7x-8y=-2\r<BR>\n" );
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document.write( "x-3y= 9     Solving Systems of Equations by Substitution </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #631893 by </B><A HREF=/tutors/aboutme.mpl?userid=macston><B>macston(5194)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=macston><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=macston><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=631893\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .<BR>\n" );
document.write( "x-3y=9 <BR>\n" );
document.write( "x=3y+9 . Use this to substitute for x in the other equation.<BR>\n" );
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document.write( "7x-8y=-2<BR>\n" );
document.write( "7(3y+9)-8y=-2<BR>\n" );
document.write( "21y+63-8y=-2<BR>\n" );
document.write( "13y+63=-2<BR>\n" );
document.write( "13y=-65<BR>\n" );
document.write( "y=-5<BR>\n" );
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document.write( "x-3y=9<BR>\n" );
document.write( "x-3(-5)=9<BR>\n" );
document.write( "x-(-15)=9<BR>\n" );
document.write( "x+15=9<BR>\n" );
document.write( "x=-6<BR>\n" );
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document.write( "ANSWER: (-6,-5)<BR>\n" );
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document.write( "CHECK:<BR>\n" );
document.write( "7x-8y=-2<BR>\n" );
document.write( "7(-6)-8(-5)=-2<BR>\n" );
document.write( "-42-(-40)=-2<BR>\n" );
document.write( "-42+40=-2<BR>\n" );
document.write( "-2=-2<BR>\n" );
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document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );