document.write( "Question 294676: use the quadratic formula to find the x-intercepts. g(x)=x^2-2x-80. \n" ); document.write( "
Algebra.Com's Answer #212468 by richwmiller(17219)\"\" \"About 
You can put this solution on YOUR website!
It is much easier to factor.
\n" ); document.write( "y = (x-10) (x+8)
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"1x%5E2%2B-2x%2B-80+=+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=%28-2%29%5E2-4%2A1%2A-80=324\".
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\n" ); document.write( " Discriminant d=324 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--2%2B-sqrt%28+324+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%28-2%29%2Bsqrt%28+324+%29%29%2F2%5C1+=+10\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%28-2%29-sqrt%28+324+%29%29%2F2%5C1+=+-8\"
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\n" ); document.write( " Quadratic expression \"1x%5E2%2B-2x%2B-80\" can be factored:
\n" ); document.write( " \"1x%5E2%2B-2x%2B-80+=+1%28x-10%29%2A%28x--8%29\"
\n" ); document.write( " Again, the answer is: 10, -8.\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%2B-2%2Ax%2B-80+%29\"
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