document.write( "Question 1069446: Let line A be the graph of 5x + 8y = -9. Line B is perpendicular to line A and passes through the point (10,10). If line B is the graph of the equation y=mx +b, then find m+b. \n" ); document.write( "

Algebra.Com's Answer #684660 by Fombitz(32388) $\"\"$ $\"About$

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$\"5x%2B8y=-9\"$
\n" ); document.write( " $\"8y=-5x-9\"$
\n" ); document.write( " $\"y=-%285%2F8%29x-9%2F8\"$
\n" ); document.write( "Perpendicular lines have slopes that are negative reciprocals,
\n" ); document.write( " $\"-%285%2F8%29m%5B2%5D=-1\"$
\n" ); document.write( " $\"m%5B2%5D=8%2F5\"$
\n" ); document.write( "So then using the point-slope form of a line,
\n" ); document.write( " $\"y-10=%288%2F5%29%28x-10%29\"$
\n" ); document.write( " $\"y-10=%288%2F5%29x-16\"$
\n" ); document.write( " $\"y=%288%2F5%29x-6\"$
\n" ); document.write( "So,
\n" ); document.write( " $\"m%2Bb=8%2F5-6=8%2F5-30%2F5=-22%2F5\"$ \n" ); document.write( "

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