document.write( "Question 1056414: X^2+4x+8=0
\n" ); document.write( "Can you find the solutions and then express them in the form a+bi? \n" ); document.write( "

Algebra.Com's Answer #671539 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"+x%5E2+%2B+4x+%2B+8+=+0+\"$
\n" ); document.write( "I can complete the square to solve
\n" ); document.write( " $\"+x%5E2+%2B+4x+=+-8+\"$
\n" ); document.write( " $\"+x%5E2+%2B+4x+%2B+%284%2F2%29%5E2+=+-8+%2B+%284%2F2%29%5E2+\"$
\n" ); document.write( " $\"+x%5E2+%2B+4x+%2B+4+=+-8+%2B+4+\"$
\n" ); document.write( " $\"+%28+x+%2B+2+%29%5E2+=+-4+\"$
\n" ); document.write( "Take the square root of both sides
\n" ); document.write( " $\"+x+%2B+2+=+sqrt%28-4%29+\"$
\n" ); document.write( " $\"+x+%2B+2+=+2i+\"$
\n" ); document.write( " $\"+x+=+-2+%2B+2i+\"$
\n" ); document.write( "and, also, taking the negative square root of $\"+-4+\"$ ,
\n" ); document.write( " $\"+x+%2B+2+=+-sqrt%28-4%29+\"$
\n" ); document.write( " $\"+x+%2B+2+=+-2i+\"$
\n" ); document.write( " $\"+x+=+-2+-+2i+\"$
\n" ); document.write( "-----------------------
\n" ); document.write( "The roots are $\"+-2+%2B+2i+\"$ and $\"+-2+-+2i+\"$
\n" ); document.write( "---------------------------------------------
\n" ); document.write( "To check, you can plug either solution for $\"+x+\"$
\n" ); document.write( "back into original equation, like this:
\n" ); document.write( " $\"+x%5E2+%2B+4x+%2B+8+=+0+\"$
\n" ); document.write( " $\"+%28+-2+%2B+2i+%29%5E2+%2B+4%2A%28+-2+%2B+2i+%29+%2B+8+=+0+\"$
\n" ); document.write( "You can do the checks\r
\n" ); document.write( "
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