document.write( "Question 293847: perpendicular to 5x + 4y = -52 through (8,4) \n" ); document.write( "
Algebra.Com's Answer #212011 by nerdybill(7384)\"\" \"About 
You can put this solution on YOUR website!
perpendicular to 5x + 4y = -52 through (8,4)
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\n" ); document.write( "First, determine the slope of:
\n" ); document.write( "5x + 4y = -52
\n" ); document.write( "Do this by changing to \"slope-intercept\" form:
\n" ); document.write( "4y = -5x-52
\n" ); document.write( "y = (-5/4)x - 13
\n" ); document.write( "Slope is -5/4
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\n" ); document.write( "For a line to be perpendicular, it must be a \"negative reciprocal\":
\n" ); document.write( "m(-5/4) = -1
\n" ); document.write( "m = (-1)(-4/5)
\n" ); document.write( "m = 4/5
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\n" ); document.write( "So, our NEW line must have
\n" ); document.write( "slope of 4/5
\n" ); document.write( "crossing (8,4)
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\n" ); document.write( "Plug the above into the \"point-slope\" form:
\n" ); document.write( "y-y1 = m(x-x1)
\n" ); document.write( "y-4 = (4/5)(x-8)
\n" ); document.write( "y-4 = (4/5)x - (4/5)8
\n" ); document.write( "y-4 = (4/5)x - 32/5
\n" ); document.write( "y = (4/5)x - 32/5 + 4
\n" ); document.write( "y = (4/5)x - 32/5 + 20/5
\n" ); document.write( "y = (4/5)x - 12/5 (this is what they're looking for)\r
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