document.write( "Question 240811: I'm having problems with writing an equation of a line that is perpendicular because our text book doesn't do a good job explaining it.
\n" ); document.write( "\"write the equation of a line that is perpendicular to the given line and that passes through the given point.\" -4x-8y=24; (4,-1) the opions they give you are
\n" ); document.write( "1.) y=2x-9
\n" ); document.write( "2.) y=1/2x+6
\n" ); document.write( "3.) y=1/2x-9
\n" ); document.write( "4.) y=-2x-9
\n" ); document.write( " I found the negative reciprocal of 4 which is -1/4 and that's as far as I have gotten. After 13 hours of doing this homework I honestly can't understand what I'm reading. \n" ); document.write( "
Algebra.Com's Answer #176437 by Alan3354(69443)\"\" \"About 
You can put this solution on YOUR website!
\"write the equation of a line that is perpendicular to the given line and that passes through the given point.\" -4x-8y=24; (4,-1) the opions they give you are
\n" ); document.write( "-----------------
\n" ); document.write( "1st find the slope of the line. Put the eqn into slope-intercept form (that means solve for y)
\n" ); document.write( "-4x-8y=24
\n" ); document.write( "-x-2y = 6
\n" ); document.write( "2y = -x - 6
\n" ); document.write( "y = (-1/2)x - 3
\n" ); document.write( "That's the form, y = mx + b. m is the slope, -1/2
\n" ); document.write( "----------------
\n" ); document.write( "The slope of all lines perpendicular is the neg recip, = +2
\n" ); document.write( "-----------------
\n" ); document.write( "Then use y = mx + b and the point to find b:
\n" ); document.write( "-1 = 2*4 + b
\n" ); document.write( "b = -9
\n" ); document.write( "That makes the eqn y = 2x - 9
\n" ); document.write( " \n" ); document.write( "
\n" );