document.write( "Question 310460: find all zeroes f(x) = x^4+6x^2-27 \n" ); document.write( "

Algebra.Com's Answer #222038 by Fombitz(32388) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"u=x%5E2\"$ , then $\"u%5E2=x%5E4\"$
\n" ); document.write( " $\"+x%5E4%2B6x%5E2-27=0\"$
\n" ); document.write( " $\"+u%5E2%2B6u-27=0\"$
\n" ); document.write( "Factor.
\n" ); document.write( " $\"%28u%2B9%29%28u-3%29\"$
\n" ); document.write( "Two solutions:
\n" ); document.write( " $\"u%2B9=0\"$
\n" ); document.write( " $\"u=-9\"$
\n" ); document.write( " $\"x%5E2=-9\"$
\n" ); document.write( " $\"x=0+%2B-+3i\"$
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\n" ); document.write( " $\"u-3=0\"$
\n" ); document.write( " $\"u=3\"$
\n" ); document.write( " $\"x%5E2=3\"$
\n" ); document.write( " $\"x=0+%2B-+sqrt%283%29\"$
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\n" ); document.write( "( $\"-sqrt%283%29\"$ , $\"sqrt%283%29\"$ , $\"-3i\"$ , $\"3i\"$ ) \n" ); document.write( "

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