document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=49878>Question 49878</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Solve the system by addition\r<BR>\n" );
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document.write( "2x-4y=7 <BR>\n" );
document.write( "4x+2y=9 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #38604 by </B><A HREF=/tutors/aboutme.mpl?userid=BGluvsmath><B>BGluvsmath(64)</B></A><img src=\"/images/stars/stars-08.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=BGluvsmath><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=38604\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 2x-4y=7<BR>\n" );
document.write( "4x+2y=9\r<BR>\n" );
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document.write( "multiply the 2nd equation by 2: 8x+4y=18<BR>\n" );
document.write( "This gives you 2x-4y=7<BR>\n" );
document.write( "               8x+4y=18<BR>\n" );
document.write( "the y terms cancel out: 10x=25<BR>\n" );
document.write( "divide both sides by 10: x=2.5\r<BR>\n" );
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document.write( "plug the x-value back into either original equation to solve for y.  For simplicity, I chose the 2nd one.<BR>\n" );
document.write( "4x+2y=9<BR>\n" );
document.write( "4(2.5)+2y=9<BR>\n" );
document.write( "10+2y=9<BR>\n" );
document.write( "2y=-1<BR>\n" );
document.write( "y=-1/2 (or -0.5)\r<BR>\n" );
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document.write( "Check: 2(2.5)-4(-0.5)=7<BR>\n" );
document.write( "5+2=7\r<BR>\n" );
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document.write( "So, the solution is (2.5, -0.5) </SPAN>\n" );
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