document.write( "Question 983273: Competing the square
\n" ); document.write( "y=3-15x-3x^2 \n" ); document.write( "

Algebra.Com's Answer #604077 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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Competing the square
\n" ); document.write( "y=3-15x-3x^2
\n" ); document.write( "rearrange to
\n" ); document.write( "-3x^2 - 15x + ___ = -3
\n" ); document.write( "we want the coefficient of x^2 to be +1, divide equation by -3
\n" ); document.write( "x^2 + 5x + ____ = 1
\n" ); document.write( "Find the square of half the coefficient of x (5), to complete the square 2.5^2 = 6.25
\n" ); document.write( "add to both sides
\n" ); document.write( "x^2 + 5x + 6.25 = 1 + 6.25
\n" ); document.write( "x^2 + 5x + 6.25 = 7.25
\n" ); document.write( "Which is
\n" ); document.write( "(x + 2.5)^2 = 7.25
\n" ); document.write( "find the square root of both sids
\n" ); document.write( "x + 2.5 = +/- $\"sqrt%287.25%29\"$
\n" ); document.write( "two solutions
\n" ); document.write( "x = -2.5 + $\"sqrt%287.25%29\"$
\n" ); document.write( "and
\n" ); document.write( "x = -2.5 - $\"sqrt%287.25%29\"$
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