document.write( "Question 509400: Find the equation of a line through the point (-1,9) and parallel to 2x-4y=7. \n" ); document.write( "

Algebra.Com's Answer #341428 by oberobic(2304) $\"\"$ $\"About$

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A line parallel to 2x-4y = 7 will have the same slope.
\n" ); document.write( "2x-4y = 7
\n" ); document.write( "-4y = -2x +7
\n" ); document.write( "y = (-2/-4)x + (7/-4)
\n" ); document.write( "y = 1/2x - 7/4
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\n" ); document.write( "Slope = 1/2
\n" ); document.write( "so the sought equation will have slope = 1/2.
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\n" ); document.write( "y = 1/2x + b
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\n" ); document.write( "We want it go through the point (-1,9),
\n" ); document.write( "so we use that point to define 'b'.
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\n" ); document.write( "9 = 1/2(-1) + b
\n" ); document.write( "9 = -1/2 + b
\n" ); document.write( "b = 9 + 1/2
\n" ); document.write( "b = 18/2 + 1/2
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\n" ); document.write( "y = 1/2x + 19/2
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\n" ); document.write( "In the following graph, the first equation is in red, the second is in green.
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\n" ); document.write( " $\"graph%28500%2C500%2C-20%2C20%2C-20%2C20%2C1%2F2%2Ax-7%2F4%2C+1%2F2%2Ax%2B19%2F2%29\"$ \n" ); document.write( "

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