document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=313263>Question 313263</A>: <I><SPAN STYLE=\"word-break: break-all;\"> .  Find the value of k such that the graphs of x + 7y = 70 and y + 3 = kx are perpendicular. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #223998 by </B><A HREF=/tutors/aboutme.mpl?userid=OmniMaestra><B>OmniMaestra(21)</B></A><img src=\"/images/stars/stars-07.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=OmniMaestra><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=OmniMaestra><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=223998\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> First find the slope of the known equation:\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+%2B+7y+=+70 ALIGN=MIDDLE  ALT=\"x+%2B+7y+=+70\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "change the equation to slope-intercept form.\r<BR>\n" );
document.write( "\n" );
document.write( "solve for y, subtract x from both sides <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7y+=+-x+%2B+70 ALIGN=MIDDLE  ALT=\"7y+=+-x+%2B+70\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "Divide both sides by 7------------------<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7y%2F7=%28-x%2F7%29+%2B+%2870%2F7%29 ALIGN=MIDDLE  ALT=\"7y%2F7=%28-x%2F7%29+%2B+%2870%2F7%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "Simplify into slope-intercept form------<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+%28-1%2F7%29x+%2B+10 ALIGN=MIDDLE  ALT=\"y+=+%28-1%2F7%29x+%2B+10\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "So the slope is -1/7. The slope of the perpendiculoar line must be the inverse reciprocal of the original. <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-1%2F7 ALIGN=MIDDLE  ALT=\"-1%2F7\"   DISABLED_style= \"max-width:90%; height:auto;\" > becomes <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=7%2F1+=+7 ALIGN=MIDDLE  ALT=\"7%2F1+=+7\"   DISABLED_style= \"max-width:90%; height:auto;\" > \r<BR>\n" );
document.write( "\n" );
document.write( "Now solve the second equation for y. ---- <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+kx+-3 ALIGN=MIDDLE  ALT=\"y+=+kx+-3\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "replace k with the new slope--------------<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=7x-3 ALIGN=MIDDLE  ALT=\"y=7x-3\"   DISABLED_style= \"max-width:90%; height:auto;\" >, so k = 7 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );