document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=312669>Question 312669</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Write an equation of the line containing the given point and perpendicular to the given line?<BR>\n" );
document.write( "(2,9)8x+y=4 and (5,-9)4x+7y=8 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #223530 by </B><A HREF=/tutors/aboutme.mpl?userid=texttutoring><B>texttutoring(324)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=texttutoring><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=texttutoring><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=223530\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Remember that perpendicular lines have slopes that are negative reciprocals of each other.\r<BR>\n" );
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document.write( "First, let's find the slope of the line. Do this by rearranging the equation so that it is in y=mx+b form.\r<BR>\n" );
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document.write( "8x+y=4<BR>\n" );
document.write( "y=-8x+4\r<BR>\n" );
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document.write( "The slope is -8. The negative reciprocal of -8 is 1/8. The perpendicular line therefore has a slope of 1/8.\r<BR>\n" );
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document.write( "Now use this slope, and the point x=2, y=9, in the y=mx+b equation to solve for b:\r<BR>\n" );
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document.write( "y=mx+b<BR>\n" );
document.write( "9=(1/8)2+b<BR>\n" );
document.write( "9=2/8 + b<BR>\n" );
document.write( "9-1/4 = b<BR>\n" );
document.write( "36/4 - 1/4 = b<BR>\n" );
document.write( "35/4 = b\r<BR>\n" );
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document.write( "The equation of the line is y=(1/8)x + 35/4\r<BR>\n" );
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document.write( "For the second question, do the same thing. Find the perpendicular slope, it's 7/4\r<BR>\n" );
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document.write( "Then use x=5 and y=-9 to solve for b:\r<BR>\n" );
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document.write( "You should find this equation:  y=(7/4)x -71/4 </SPAN>\n" );
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