document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=988090>Question 988090</A>: <I><SPAN STYLE=\"word-break: break-all;\"> please help me understand how to determine if these pairs of lines are perpendicular parallel or neither:\r<BR>\n" );
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document.write( "1.y=-4x-4<BR>\n" );
document.write( "2. 8x-2y=-2<BR>\n" );
document.write( "3.y=4x+8 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #608710 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=608710\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Put them all into the form of y=mx+b and compare m.<BR>\n" );
document.write( "first is y=-4x-4<BR>\n" );
document.write( "second is -2y=-8x-2; divide by -2; y=4x+1<BR>\n" );
document.write( "third is y=4x+8<BR>\n" );
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document.write( "Same slopes, different intercepts, parallel.<BR>\n" );
document.write( "Different slopes, which when multiplied together are not -1: neither.  If multiplication of slopes is -1, then the lines are perpendicular.  That is all you have to do.<BR>\n" );
document.write( "The second and third have the same slope, so they are parallel.  The first has a slope of -4, but since -4*4=-16 and not -1, they intersect and are not perpendicular.\r<BR>\n" );
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