document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=196556>Question 196556</A>: <I><SPAN STYLE=\"word-break: break-all;\"> In the graph of the equation ax+3y=9 is perpendicular to the graph of the equation 3x+y=-4, find the value a </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #147299 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=147299\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> In the graph of the equation ax+3y=9 is perpendicular to the graph of the equation 3x+y=-4, find the value a<BR>\n" );
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document.write( "3x+y=-4 --> y = -3x - 4 so its slope, m1, = -3<BR>\n" );
document.write( "The slope of lines perpendicular will have the negative inverse slope, +1/3.<BR>\n" );
document.write( "ax+3y=9<BR>\n" );
document.write( "Put into slope-intercept form (that means solve for y)<BR>\n" );
document.write( "3y = -ax + 9<BR>\n" );
document.write( "y = (-a/3)x + 3<BR>\n" );
document.write( "m2 = +1/3 = -a/3<BR>\n" );
document.write( "a = -1<BR>\n" );
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