document.write( "Question 295760: Solve (2x - 1)^2 = 20 Show every step \n" ); document.write( "
Algebra.Com's Answer #213191 by JBarnum(2146)\"\" \"About 
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\"%282x-1%29%5E2=20\" show full problem
\n" ); document.write( "\"%282x-1%29%282x-1%29=20\"foil
\n" ); document.write( "\"4x%5E2-2x-2x%2B1=20\" add like terms
\n" ); document.write( "\"4x%5E2-4x%2B1=20\" subtract 20
\n" ); document.write( "\"4x%5E2-4x-19=0\"
\n" ); document.write( "use quadratic formula
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Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"4x%5E2%2B-4x%2B-19+=+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=%28-4%29%5E2-4%2A4%2A-19=320\".
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\n" ); document.write( " Discriminant d=320 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--4%2B-sqrt%28+320+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%28-4%29%2Bsqrt%28+320+%29%29%2F2%5C4+=+2.73606797749979\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%28-4%29-sqrt%28+320+%29%29%2F2%5C4+=+-1.73606797749979\"
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\n" ); document.write( " Quadratic expression \"4x%5E2%2B-4x%2B-19\" can be factored:
\n" ); document.write( " \"4x%5E2%2B-4x%2B-19+=+4%28x-2.73606797749979%29%2A%28x--1.73606797749979%29\"
\n" ); document.write( " Again, the answer is: 2.73606797749979, -1.73606797749979.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+4%2Ax%5E2%2B-4%2Ax%2B-19+%29\"

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