document.write( "Question 964814: -5y = +4x + 7
\n" ); document.write( "-20x + py = -3\r
\n" ); document.write( "\n" ); document.write( "What value of p makes this system inconsistent?
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Algebra.Com's Answer #589706 by Theo(13342)\"\" \"About 
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solve for y in both equations and place the solution in slope intercept form of y = mx + b here m is the slope and b is the y-intercept.\r
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\n" ); document.write( "\n" ); document.write( "first equation is -5y = 4x + 7
\n" ); document.write( "divide both sides of the equation by -5 to get:
\n" ); document.write( "y = -4/5*x - 7/5
\n" ); document.write( "m = -4/5
\n" ); document.write( "b = -7/5\r
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\n" ); document.write( "\n" ); document.write( "second equation is -20x + py = -3
\n" ); document.write( "add 20x to both sides to get py = 20x - 3
\n" ); document.write( "divide both sides by p to get y = 20x/p - 3/p
\n" ); document.write( "m = 20x/p
\n" ); document.write( "b = -3/p\r
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\n" ); document.write( "\n" ); document.write( "for the system to be inconsistent, the lines have to be parallel.
\n" ); document.write( "then there is no solution that is common to both lines.\r
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\n" ); document.write( "\n" ); document.write( "the lines are parallel if their slopes are the same and their y-intercepts are different.\r
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\n" ); document.write( "\n" ); document.write( "slope of the first line is -4/5
\n" ); document.write( "slope of the second line is 20/p\r
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\n" ); document.write( "\n" ); document.write( "you need to find the value of p that makes -4/5 equal to 20/p\r
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\n" ); document.write( "\n" ); document.write( "set up the equation of -4/5 = 20/p\r
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\n" ); document.write( "\n" ); document.write( "cross multiply to get -4p = 100
\n" ); document.write( "divide by -4 to get p = 100/-4 which makes p = -25.\r
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\n" ); document.write( "\n" ); document.write( "when p = -25, the equation of y = 20x/p -3 becomes y = 20x/-25 - 3/25.\r
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\n" ); document.write( "\n" ); document.write( "simplify this to get y = -4/5 * x - 3/25.\r
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\n" ); document.write( "\n" ); document.write( "the slope is the same and the y-intercept is different so the lines are parallel.\r
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\n" ); document.write( "\n" ); document.write( "here's the graph of both equations.\r
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\n" ); document.write( "\n" ); document.write( "first equation is y = -4/5 * x - 7/5
\n" ); document.write( "second equation is y = -4/5 * x - 3/25\r
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\n" ); document.write( "\n" ); document.write( "\"graph%28600%2C600%2C-10%2C10%2C-10%2C10%2C-4%2F5%2Ax-7%2F5%2C-4%2F5%2Ax-3%2F25%29\"\r
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\n" ); document.write( "\n" ); document.write( "the lines are parallel.
\n" ); document.write( "they will never intersect.
\n" ); document.write( "the system is inconsistent which means that there is no solution.\r
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