document.write( "Question 49409: Solve by completing the square.
\n" ); document.write( " x2 + 2x – 15 = 0
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Algebra.Com's Answer #32813 by Earlsdon(6294) $\"\"$ $\"About$

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Solve by completing the square:\r
\n" ); document.write( "\n" ); document.write( " $\"x%5E2%2B2x-15+=+0\"$ First, add 15 to both sides of the equation.
\n" ); document.write( " $\"x%5E2%2B2x+=+15\"$
\n" ); document.write( "Since the coefficient of the $\"x%5E2\"$ term is 1, you can complete the square by adding the square of half the coefficient of the x-term, which is: $\"%282%2F2%29%5E2+=+1\"$ , to both sides of the equation.
\n" ); document.write( " $\"x%5E2%2B2x%2B1+=+16\"$ Now factor the left sides of the equation.
\n" ); document.write( " $\"%28x%2B1%29%5E2+=+16\"$ Next, take the square root of both sides.
\n" ); document.write( " $\"x%2B1+=+sqrt%2816%29\"$ and $\"x%2B1+=+-sqrt%2816%29\"$ Finally, solve for x.
\n" ); document.write( " $\"x+=+-1%2Bsqrt%2816%29\"$ $\"x+=+-1%2B4\"$ $\"x+=+3\"$
\n" ); document.write( " $\"x+=+-1-sqrt%2816%29\"$ $\"x+=+-1-4\"$ $\"x+=+-5\"$ \n" ); document.write( "

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