document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=927554>Question 927554</A>: <I><SPAN STYLE=\"word-break: break-all;\"> How do I find X and Y by using substitution?\r<BR>\n" );
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document.write( "2x + y = 0<BR>\n" );
document.write( "x - 3y = -7 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #563048 by </B><A HREF=/tutors/aboutme.mpl?userid=Techpriest><B>Techpriest(29)</B></A><img src=\"/images/stars/stars-07.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Techpriest><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=563048\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Well, you see you would need to use substitution, you can find either the x-value or y-value preferring your choice. In order to find that, we must find the x-value or y-value through equality properties for the first equation:<BR>\n" );
document.write( "2x + y = 0<BR>\n" );
document.write( "2x - 2x + y = 0 - 2x Subtraction Property of Equality<BR>\n" );
document.write( "y = -2x Simplify\r<BR>\n" );
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document.write( "OR\r<BR>\n" );
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document.write( "2x + y = 0<BR>\n" );
document.write( "2x + y - y = 0 - y Subtraction Property of Equality<BR>\n" );
document.write( "2x = -y Simplify<BR>\n" );
document.write( "2x/2 = -y/2 Division Property of Equality<BR>\n" );
document.write( "x = -y/2 Simplify\r<BR>\n" );
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document.write( "Or we can do the same for the second equation:<BR>\n" );
document.write( "x - 3y = -7 <BR>\n" );
document.write( "x - x - 3y = -7 - x Subtraction Property of Equality<BR>\n" );
document.write( "-3y = -7 - x Simplify<BR>\n" );
document.write( "-3y/-3 = (-7 - x)/-3 Division Property of Equality<BR>\n" );
document.write( "y = (-7 - x)/-3 Simplify\r<BR>\n" );
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document.write( "OR\r<BR>\n" );
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document.write( "x - 3y = -7 <BR>\n" );
document.write( "x - 3y + 3y = -7 + 3y Addition Property of Equality<BR>\n" );
document.write( "x = -7 + 3y Simplify\r<BR>\n" );
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document.write( "You may choose whichever is easier for you. After finding the x-value or y-value, you must substitute them in. I will substitute my first example for the easiness in for the second equation as the first example will always be true for the first equation.\r<BR>\n" );
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document.write( "y = -2x<BR>\n" );
document.write( "x - 3y = -7<BR>\n" );
document.write( "x - 3(-2x) = -7<BR>\n" );
document.write( "x + 6x = -7<BR>\n" );
document.write( "7x = -7<BR>\n" );
document.write( "x = -1\r<BR>\n" );
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document.write( "Now, if we plug in x for the y-value, we will find out that:<BR>\n" );
document.write( "x = -1<BR>\n" );
document.write( "y = -2x<BR>\n" );
document.write( "y = -2(-1)<BR>\n" );
document.write( "y = 2<BR>\n" );
document.write( "x = -1, y = 2\r<BR>\n" );
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document.write( "If we plug in the x-value and y-value for both of those equation, they will be true, which gives you your answer!<BR>\n" );
document.write( "2x + y = 0<BR>\n" );
document.write( "2(-1) + -2 = 0 Substitution!<BR>\n" );
document.write( "2 + -2 = 0 Simplify<BR>\n" );
document.write( "0 = 0\r<BR>\n" );
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document.write( "x - 3y = -7<BR>\n" );
document.write( "-1 - 3(2) = -7 Substitution<BR>\n" );
document.write( "-1 - 6 = -7 Simplify<BR>\n" );
document.write( "-7 = -7 Combine like terms.<BR>\n" );
document.write( " </SPAN>\n" );
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