document.write( "Question 735628: without graphing,tell whether the graphs of the equations are parallel, perpendicular, or neither. justify your answers using complete sentences. m(x)= -5x + 123/7 and x+5y= -12 \n" ); document.write( "

Algebra.Com's Answer #449489 by MathLover1(20850) $\"\"$ $\"About$

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$\"m%28x%29=+-5x+%2B+123%2F7\"$ and $\"x%2B5y=+-12+\"$ \r
\n" ); document.write( "\n" ); document.write( "firs write them in slope-intercept form: $\"y=mx%2Bb\"$ where $\"m=slope\"$ and $\"b=y-intercept\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"m%28x%29=+-5x+%2B+123%2F7\"$ ..already in slope-intercept form: $\"m=-5\"$ and $\"b=+123%2F7\"$ \r
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\n" ); document.write( "\n" ); document.write( " $\"x%2B5y=+-12+\"$ ...solve for $\"y\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"5y=+-x-12+\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"y=+%28-1%2F5%29x-12%2F5+\"$ .... $\"m=-1%2F5\"$ and $\"b=+12%2F5\"$ \r
\n" ); document.write( "\n" ); document.write( "take a look at slopes: $\"m=-5\"$ and $\"m=-1%2F5\"$ \r
\n" ); document.write( "\n" ); document.write( "lines that are parallel have $\"same\"$ $\"slope\"$ : since $\"-5%3C%3E-1%2F5\"$ , these line are not parallel\r
\n" ); document.write( "\n" ); document.write( "to be perpendicular, lines have to have slopes negative reciprocals of each other
\n" ); document.write( "as you can see, $\"5\"$ and $\"1%2F5\"$ are reciprocals, but you have $\"-5\"$ and $\"-1%2F5\"$ ; so, since both negative, one is $\"not\"$ negative reciprocal of other one\r
\n" ); document.write( "\n" ); document.write( "therefore,these line are not perpendicular ether \r
\n" ); document.write( "\n" ); document.write( "so, these lines are neither parallel nor perpendicular, they must be intersecting in one point\r
\n" ); document.write( "\n" ); document.write( "let's check it on a graph:\r
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