document.write( "Question 49596: solve by completing the square(DO NOT FACTOR): x^2-4x-12 \n" ); document.write( "

Algebra.Com's Answer #32924 by Earlsdon(6294) $\"\"$ $\"About$

You can put this solution on YOUR website!
Solve by completing the square:
\n" ); document.write( " $\"x%5E2-4x-12\"$ Unfortunately you cannot \"solve\" this \"expression\". Now if this expression were equal to something, say equal to 0, then it could be solved because then it would be an \"equation\".
\n" ); document.write( "So, let's assume that you forgot to type \"...= 0\" and see what can be done.\r
\n" ); document.write( "\n" ); document.write( " $\"x%5E2-4x-12+=+0\"$ First, add 12 to both sides of the equation.
\n" ); document.write( " $\"x%5E2-4x+=+12\"$ Now add the square of half the x-coefficient $\"%28-4%2F2%29%5E2+=+4\"$ to both sides.
\n" ); document.write( " $\"x%5E2-4x%2B4+=+16\"$ Factor the left side.
\n" ); document.write( " $\"%28x-2%29%5E2+=+16\"$ Take the square root of both sides.
\n" ); document.write( " $\"x-2+=+4\"$ and $\"x-2+=+-4\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"x+=+6\"$ and $\"x+=+-2\"$
\n" ); document.write( " \n" ); document.write( "

\n" );