document.write( "Question 189419: I cant figure this one out. Please help.\r
\n" ); document.write( "\n" ); document.write( "Solve the equation x2 + 8x – 2 = 0 using both
\n" ); document.write( "a) The quadratic formula\r
\n" ); document.write( "\n" ); document.write( "b) Completing the square\r
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\n" ); document.write( "\n" ); document.write( "Prepare a few sentences comparing and contrasting the two methods
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Algebra.Com's Answer #142106 by Mathtut(3670)\"\" \"About 
You can put this solution on YOUR website!
b)\"x%5E2%2B8x%2B16-16-2=0\"
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\n" ); document.write( "\"%28x%2B4%29%5E2=18\"
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\n" ); document.write( "\"x%2B4=sqrt%2818%29\" and \"x%2B4=-sqrt%2818%29\"
\n" ); document.write( ":
\n" ); document.write( "\"x=-4%2B3sqrt%282%29\" and \"x=-4-3sqrt%282%29\"
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\n" ); document.write( "a)\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"1x%5E2%2B8x%2B-2+=+0\") has the following solutons:
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\n" ); document.write( " \"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
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\n" ); document.write( " For these solutions to exist, the discriminant \"b%5E2-4ac\" should not be a negative number.
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\n" ); document.write( " First, we need to compute the discriminant \"b%5E2-4ac\": \"b%5E2-4ac=%288%29%5E2-4%2A1%2A-2=72\".
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\n" ); document.write( " Discriminant d=72 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-8%2B-sqrt%28+72+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%288%29%2Bsqrt%28+72+%29%29%2F2%5C1+=+0.242640687119285\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%288%29-sqrt%28+72+%29%29%2F2%5C1+=+-8.24264068711928\"
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\n" ); document.write( " Quadratic expression \"1x%5E2%2B8x%2B-2\" can be factored:
\n" ); document.write( " \"1x%5E2%2B8x%2B-2+=+%28x-0.242640687119285%29%2A%28x--8.24264068711928%29\"
\n" ); document.write( " Again, the answer is: 0.242640687119285, -8.24264068711928.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+1%2Ax%5E2%2B8%2Ax%2B-2+%29\"

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