document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=26356>Question 26356</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 2x + 3y=21<BR>\n" );
document.write( "4x + 2y =22 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #14212 by </B><A HREF=/tutors/aboutme.mpl?userid=wuwei96815><B>wuwei96815(245)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=wuwei96815><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=14212\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Multiply first equation by -2.  We get -4x - 6y = -42.\r<BR>\n" );
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document.write( "Now, add the altered first equation to the second equation.  We get -4y = -20.\r<BR>\n" );
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document.write( "Solve -4y = -20.  We get y = -20/-4 = 5.\r<BR>\n" );
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document.write( "Now that we have the value for y we can go back and substitute this value in either of the original equations and solve for x.  Let's use the first equation.<BR>\n" );
document.write( "2x +3y = 21<BR>\n" );
document.write( "2x +3(5) = 21<BR>\n" );
document.write( "2x +15 = 21<BR>\n" );
document.write( "2x = 21 - 15 = 6<BR>\n" );
document.write( "x = 6/2 = 3\r<BR>\n" );
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document.write( "This method for finding two unknowns with two equations is called the addition/substitution method.  There are other methods for doing this problem also. </SPAN>\n" );
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