document.write( "Question 252192: In an (x, y) coordinate system, write the equation of the vertical line passing
\n" ); document.write( "through the point of intersection of 3x + 4y = 1 and x + 3y = 7 . \n" ); document.write( "
Algebra.Com's Answer #183958 by nerdybill(7384)\"\" \"About 
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In an (x, y) coordinate system, write the equation of the vertical line passing
\n" ); document.write( "through the point of intersection of 3x + 4y = 1 and x + 3y = 7 .
\n" ); document.write( ".
\n" ); document.write( "First, find out where the two lines intersect:
\n" ); document.write( "3x + 4y = 1
\n" ); document.write( " x + 3y = 7
\n" ); document.write( ".
\n" ); document.write( "Multiply second equation by -3:
\n" ); document.write( " 3x + 4y = 1
\n" ); document.write( "-3x - 9y = -21
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\n" ); document.write( "Add the two equations together:
\n" ); document.write( " 3x + 4y = 1
\n" ); document.write( "-3x - 9y = -21
\n" ); document.write( "----------------
\n" ); document.write( " -5y = -20
\n" ); document.write( " y = 4
\n" ); document.write( ".
\n" ); document.write( "Use the second equation to find x:
\n" ); document.write( " x + 3y = 7
\n" ); document.write( " x + 3(4) = 7
\n" ); document.write( " x + 12 = 7
\n" ); document.write( " x = -5 (which is also the vertical line they are looking for)
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