document.write( "Question 89506: Solve by completing the square.
\n" ); document.write( " x2 – 2x – 15 = 0
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #65058 by funmath(2933) $\"\"$ $\"About$

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Solve by completing the square.
\n" ); document.write( " x2 – 2x – 15 = 0
\n" ); document.write( "x^2-2x-15+15=0+15
\n" ); document.write( "x^2-2x+___=15+___
\n" ); document.write( "fill the blank with (b/2)^2 (b is the coefficient of x)
\n" ); document.write( "x^2-2x+(-2/2)^2=15+(-2/2)^2
\n" ); document.write( "x^2-2x+(-1)^2=15+(-1)^2
\n" ); document.write( "x^2-2x+1=15+1
\n" ); document.write( "x^2-2x+1=16
\n" ); document.write( "Now you have a perfect square trinomial that can be factored like this.
\n" ); document.write( "(x-1)^2=16
\n" ); document.write( " $\"sqrt%28%28x-1%29%5E2%29=%2B-sqrt%2816%29\"$
\n" ); document.write( "x-1=+/-4
\n" ); document.write( "x-1+1=1+/-4
\n" ); document.write( "x=1+/-4
\n" ); document.write( "x=1-4 or x=1+4
\n" ); document.write( "x=-3 or x=5
\n" ); document.write( "Happy Calculating!!! \n" ); document.write( "

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