document.write( "Question 27185: 25. Are the following lines parallel, perpendicular, or neither?
\n" ); document.write( " L1 with equation x – 3y = 12
\n" ); document.write( " L2 with equation 3x + y = 3
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Algebra.Com's Answer #14775 by rodriguezh2(15)\"\" \"About 
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Whenever you have this type of problem you must make sure both equations are in y = mx + b form. Remember m = slope and b = (y)intercept.\r
\n" ); document.write( "\n" ); document.write( "L1 with equation x - 3y = 12 becomes y = (x/3) - 4
\n" ); document.write( "L2 with equation 3x + y = 3 becomes y = -3x +3\r
\n" ); document.write( "\n" ); document.write( "Parallel lines have the same slope. Therefore the m from L1 and the m from L2 must be equal. We see that (x/3) does not equal -3x so these two lines cannot be parallel.\r
\n" ); document.write( "\n" ); document.write( "Perpendicular lines have negative (-) reciprocal slope.
\n" ); document.write( "( ex: 2x and -(1/2)x.)
\n" ); document.write( " Since m = (x/3) from L1 and m = -3x in L2 we can say that these are negative reciprocals and so therefore these two lines are perpendicular.
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