document.write( "Question 1128884: Given the following two linear equations, determine whether the lines are parallel, perpendicular, or neither. Show all work and explain your conclusion fully.\r
\n" ); document.write( "\n" ); document.write( "5x+4y=40
\n" ); document.write( "16x=15+20y\r
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Algebra.Com's Answer #745417 by KMST(5328)\"\" \"About 
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The key to the answer is finding the slope for the lines.
\n" ); document.write( "Solve each equation for y to find the slope-intercept form of each equation.
\n" ); document.write( "\"5x%2B4y=40\" --> \"4y=40-5x\" --> \"y=40%2F4-5x%2F4\" --> \"y=%28-5%2F4%29x%2B10\"
\n" ); document.write( "\"16x=15%2B20y\" --> \"16x-15=20y\" --> \"y=16x%2F20-15%2F20\" --> \"y=%284%2F5%29x-3%2F4\" \r
\n" ); document.write( "\n" ); document.write( "we got different expressions for y, so the lines are not the same line in disguise.
\n" ); document.write( "The slopes (the coefficients of x) are \"-5%2F4\" and \"4%2F5\" .
\n" ); document.write( "Their product is
\n" ); document.write( "\"%28-5%2F4%29%284%2F5%29=-1\" .
\n" ); document.write( "The fact that the product is \"-1\" means that the lines are perpendicular.
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