document.write( "Question 625211: This is actually for QUADRATIC FORMULA, NOT QUADRATIC EQUATION\r
\n" ); document.write( "\n" ); document.write( "Solve by completing the square\r
\n" ); document.write( "\n" ); document.write( "2x^2 + 11x - 1 = 0\r
\n" ); document.write( "\n" ); document.write( "The solution set is { } \n" ); document.write( "

Algebra.Com's Answer #393391 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"+2x%5E2+%2B+11x+-+1+=+0+\"$
\n" ); document.write( "First add $\"+1+\"$ to both sides
\n" ); document.write( " $\"+2x%5E2+%2B+11x+=+1+\"$
\n" ); document.write( "Now divide both sides by $\"+2+\"$
\n" ); document.write( " $\"+x%5E2+%2B+%2811%2F2%29%2Ax+=+1%2F2+\"$
\n" ); document.write( "------------
\n" ); document.write( "In order to complete the square, take
\n" ); document.write( "1/2 of the coefficient of the $\"+x+\"$ term,
\n" ); document.write( "square it, then add it to both sides
\n" ); document.write( "------------------
\n" ); document.write( " $\"+x%5E2+%2B+%2811%2F2%29%2Ax+%2B+%2811%2F4%29%5E2+=+1%2F2+%2B+%2811%2F4%29%5E2+\"$
\n" ); document.write( " $\"+x%5E2+%2B+%2811%2F2%29%2Ax+%2B+121%2F16+=+8%2F16+%2B+121%2F16+\"$
\n" ); document.write( " $\"+%28+x+%2B+11%2F4+%29%5E2+=+129%2F16+\"$
\n" ); document.write( "Take the square root of both sides
\n" ); document.write( " $\"+x+%2B+11%2F4+=+sqrt%28129%29%2F4+\"$
\n" ); document.write( " $\"+x+=+%28+-11+%2B+sqrt%28129%29+%29+%2F+4+\"$
\n" ); document.write( "and
\n" ); document.write( " $\"+x+=+%28+-11+-+sqrt%28129%29+%29+%2F+4+\"$
\n" ); document.write( "-------------------------
\n" ); document.write( "check:
\n" ); document.write( " $\"+2x%5E2+%2B+11x+-+1+=+0+\"$
\n" ); document.write( "

\n" ); document.write( "

\n" ); document.write( " $\"+121%2F8+%2B+129%2F8+-242%2F8+-+8%2F8+=+0+\"$
\n" ); document.write( " $\"+250%2F8+-+250%2F8+=+0+\"$
\n" ); document.write( " $\"+0+=+0+\"$
\n" ); document.write( "OK
\n" ); document.write( "You can check other root \n" ); document.write( "

\n" );