document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=549455>Question 549455</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The equations of two lines are given as x + 3y = 0 and 2x - y= -7. What are the coordinates of the point of intersection.\r<BR>\n" );
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document.write( "How do I solve this\r<BR>\n" );
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document.write( "Thank you,<BR>\n" );
document.write( "Natasha </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #357761 by </B><A HREF=/tutors/aboutme.mpl?userid=TutorDelphia><B>TutorDelphia(193)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=TutorDelphia><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=TutorDelphia><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=357761\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Hi Natasha, <BR>\n" );
document.write( "Finding x and y and writing them as an ordered pair (x,y) is what your teacher is looking for here.\r<BR>\n" );
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document.write( "With systems of equations there are three ways to solve it, graphing, substitution or elimination. \r<BR>\n" );
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document.write( "I'll show you elimination and graphing.\r<BR>\n" );
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document.write( "x + 3y = 0 and <BR>\n" );
document.write( "2x - y= -7\r<BR>\n" );
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document.write( "Lets multiply both sides of the second equation by 3\r<BR>\n" );
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document.write( "6x-3y=-21<BR>\n" );
document.write( "Now lets add the two equations<BR>\n" );
document.write( "6x-3y=-21<BR>\n" );
document.write( "x + 3y = 0<BR>\n" );
document.write( "7x=-21<BR>\n" );
document.write( "x=-3\r<BR>\n" );
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document.write( "We can then plug in -3 for x to find y<BR>\n" );
document.write( "2*(-3)-y=-7<BR>\n" );
document.write( "y=1\r<BR>\n" );
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document.write( "so your answer is (-3,1)\r<BR>\n" );
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document.write( "To graph we have to have the equations in slope intercept form<BR>\n" );
document.write( "x + 3y = 0<BR>\n" );
document.write( "3y=-x<BR>\n" );
document.write( "y=-x/3<BR>\n" );
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document.write( "2x - y= -7<BR>\n" );
document.write( "-y=-2x-7<BR>\n" );
document.write( "y=2x+7<BR>\n" );
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document.write( "and we see they intersect at (-3,1) </SPAN>\n" );
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