document.write( "Question 108379: completing the square\r
\n" ); document.write( "\n" ); document.write( "-1/2x²+4x-6=0
\n" ); document.write( "

Algebra.Com's Answer #79012 by Fombitz(32388)\"\" \"About 
You can put this solution on YOUR website!
\"-%281%2F2%29x%5E2%2B4x-6=0\"
\n" ); document.write( "Let's multiply both sides by (-2) to get rid of the fraction.
\n" ); document.write( "\"%28-2%29%28-%281%2F2%29x%5E2%2B4x-6%29=0\"
\n" ); document.write( "\"x%5E2-8x%2B12=0\"Simplify.
\n" ); document.write( "We want to find a constant, a, such that,
\n" ); document.write( "\"%28x%2Ba%29%5E2=x%5E2%2B2ax%2Ba%5E2\"Expand the perfect square equation.
\n" ); document.write( "Compare coefficients of that equation with your equation,
\n" ); document.write( "\"2ax=-8x\"
\n" ); document.write( "\"a=-4\"
\n" ); document.write( "If a=-4, the \"a%5E2=16\".
\n" ); document.write( "In order get get 16 on the left hand side of the equation, that is, in order to complete the square, you need to add 4 to the left hand side.
\n" ); document.write( "Whatever you do to one side of the equation, you must do to the other side.
\n" ); document.write( "\"x%5E2-8x%2B12=0\"
\n" ); document.write( "\"x%5E2-8x%2B16=4\"Add 4 to both sides.
\n" ); document.write( "\"%28x-4%29%5E2=4\"Complete the square.
\n" ); document.write( "\"x-4=2\" and \"x-4=-2\"
\n" ); document.write( "\"x-4=2\"
\n" ); document.write( "\"highlight%28x=6%29\"
\n" ); document.write( "\"x-4=-2\"
\n" ); document.write( "\"highlight%28x=2%29\"
\n" ); document.write( "Check your answers.
\n" ); document.write( "\"-%281%2F2%29x%5E2%2B4x-6=0\"
\n" ); document.write( "\"-%281%2F2%29%286%29%5E2%2B4%286%29-6=0\"
\n" ); document.write( "\"-18%2B24-6=0\"
\n" ); document.write( "\"0=0\"
\n" ); document.write( "\"-%281%2F2%29x%5E2%2B4x-6=0\"
\n" ); document.write( "\"-%281%2F2%29%282%29%5E2%2B4%282%29-6=0\"
\n" ); document.write( "\"-2%2B8-6=0\"
\n" ); document.write( "\"0=0\"
\n" ); document.write( "Both answers lead to true statements.
\n" ); document.write( "Good answers.
\n" ); document.write( "
\n" );