document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1025811>Question 1025811</A>: <I><SPAN STYLE=\"word-break: break-all;\"> two  lines, L1 and L2, intersect at (4,7) and are perpendicular to each other. the y-intercept of L1 is 9 <BR>\n" );
document.write( "what is the gradient of L1???<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #641115 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39618)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=641115\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find first the equation for Line_1.\r<BR>\n" );
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document.write( "Two points on Line_1 are (0,9) and (4,7).<BR>\n" );
document.write( "Slope is  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%287-9%29%2F%284-0%29=-2%2F4=-1%2F2 ALIGN=MIDDLE  ALT=\"%287-9%29%2F%284-0%29=-2%2F4=-1%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "Equation for Line_1 is  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=-%281%2F2%29x%2B9 ALIGN=MIDDLE  ALT=\"y=-%281%2F2%29x%2B9\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
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document.write( "The question of finding gradient of Line_1 reads like you want the slope;<BR>\n" );
document.write( "which is now found, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-1%2F2 ALIGN=MIDDLE  ALT=\"-1%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" >, for LINE_1.\r<BR>\n" );
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document.write( "The slope of Line_2 is the negative reciprocal of  that of line_1 because these<BR>\n" );
document.write( "two lines were given as perpendicular, so Line_2 has slope <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2 ALIGN=MIDDLE  ALT=\"2\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
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