document.write( "Question 158073: Can someone help me with this one.
\n" ); document.write( "Determine whether the graphs of the equations are parallel lines, perpendicular lines or niether.
\n" ); document.write( "3x - 8y = -18
\n" ); document.write( "32x + 12y = -18
\n" ); document.write( "Thank you!
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Algebra.Com's Answer #116466 by Earlsdon(6294)\"\" \"About 
You can put this solution on YOUR website!
To determine whether the graphs of the given equations are perpendicular lines, parallel lines, or neither, you need ony to compare their slopes.
\n" ); document.write( "Perpendicular lines have negative reciprocal slopes.
\n" ); document.write( "Parallel lines have equal slopes, and neither have neither!
\n" ); document.write( "So, let's get the equations into their \"slope-intercept\" forms: y=mx+b.
\n" ); document.write( "1) \"3x-8y+=+-18\" Add 8y to both sides.
\n" ); document.write( "\"3x+=+8y-18\" Add 18 to both sides.
\n" ); document.write( "\"3x%2B18+=+8y\" Divide both sides by 8.
\n" ); document.write( "\"highlight%28y+=+%283%2F8%29x%2B9%2F4%29\" The slope here is:\"highlight%28m%5B1%5D+=+3%2F8%29\"
\n" ); document.write( "2) \"32x%2B12y+=+-18\" Subtract 2x from both sides.
\n" ); document.write( "\"12y+=+-32x-18\" Divide both sides by 12.
\n" ); document.write( "\"highlight%28y+=+%28-8%2F3%29x-9%2F6%29\" The slope here is: \"highlight%28m%5B2%5D+=+-8%2F3%29\"
\n" ); document.write( "Comparing \"m%5B1%5D+=+3%2F8\" with \"m%5B2%5D+=+-8%2F3\", you can see that they are negative reciprocals and, therefore, their graphs of the equations will be perpendicular lines.
\n" ); document.write( "For confirmation, we'll graph the two equations. Red = equation 1). Green = equation 2).
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