document.write( "Question 801034: Solve the equation by completing the square: Solve the equation by completing the square: 4x^2-4x-9=0
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Algebra.Com's Answer #483540 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

You can put this solution on YOUR website!
complete the square:
\n" ); document.write( "4x^2 - 4x - 9 = 0
\n" ); document.write( "we want the coefficient of x^2 to be 1, divide eq by 4
\n" ); document.write( "x^2 - x - $\"9%2F4\"$ = 0
\n" ); document.write( "x^2 - x + __ = $\"9%2F4\"$
\n" ); document.write( "to complete the square, take half the coefficient of x, and square it
\n" ); document.write( "That's (1/2)^2 = 1/4, add to both sides
\n" ); document.write( "x^2 - x + $\"1%2F4\"$ = $\"9%2F4\"$ + $\"1%2F4\"$
\n" ); document.write( "x^2 - x + $\"1%2F4\"$ = $\"10%2F4\"$
\n" ); document.write( "we can write it
\n" ); document.write( "{x - $\"1%2F2\"$ )^2 = $\"10%2F4\"$
\n" ); document.write( "Find the square root of both sides
\n" ); document.write( "x - $\"1%2F2\"$ = +/- $\"sqrt%2810%2F4%29\"$
\n" ); document.write( "x = $\"1%2F2\"$ +/- $\"sqrt%2810%2F4%29\"$
\n" ); document.write( "extract the square root of 1/4
\n" ); document.write( "x = $\"1%2F2\"$ +/- $\"%281%2F2%29sqrt%2810%29\"$
\n" ); document.write( "write the two solutions as
\n" ); document.write( "x = $\"%281%2Bsqrt%2810%29%29%2F2\"$
\n" ); document.write( "and
\n" ); document.write( "x = $\"%281-sqrt%2810%29%29%2F2\"$
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