document.write( "Question 387384: Could someone work this out step by step for me. I do not understand. I am lost.\r
\n" ); document.write( "\n" ); document.write( "b^4+13b^2+36=0\r
\n" ); document.write( "\n" ); document.write( "Thank you so much. \n" ); document.write( "

Algebra.Com's Answer #273823 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
I can say $\"k+=+b%5E2\"$
\n" ); document.write( "The equation becomes
\n" ); document.write( " $\"k%5E2+%2B+13k+%2B+36+=+0\"$
\n" ); document.write( "Using the quadratic formula:
\n" ); document.write( " $\"k+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"$
\n" ); document.write( "where
\n" ); document.write( " $\"a+=+1\"$
\n" ); document.write( " $\"b+=+13\"$
\n" ); document.write( " $\"c+=+36\"$
\n" ); document.write( " $\"k+=+%28-13+%2B-+sqrt%28+13%5E2-4%2A1%2A36+%29%29%2F%282%2A1%29+\"$
\n" ); document.write( " $\"k+=+%28-13+%2B-+sqrt%28+169+-+144+%29%29%2F2+\"$
\n" ); document.write( " $\"k+=+%28-13+%2B-+sqrt%28+25+%29%29%2F2+\"$
\n" ); document.write( " $\"k+=+%28-13+%2B+5%29%2F2\"$
\n" ); document.write( " $\"k+=+-4\"$
\n" ); document.write( "and
\n" ); document.write( " $\"k+=+%28-13+-+5%29%2F2\"$
\n" ); document.write( " $\"k+=+-9\"$
\n" ); document.write( "And, since
\n" ); document.write( " $\"k+=+b%5E2\"$
\n" ); document.write( " $\"-4+=+b%5E2\"$
\n" ); document.write( " $\"b+=+2i\"$
\n" ); document.write( "and
\n" ); document.write( " $\"-9+=+b%5E2\"$
\n" ); document.write( " $\"b+=+3i\"$
\n" ); document.write( "The roots are imaginary
\n" ); document.write( "If I put $\"b+=+3i\"$ back into the equation:
\n" ); document.write( " $\"%283i%29%5E4+%2B+13%2A%283i%29%5E2+%2B+36+=+0\"$
\n" ); document.write( " $\"81+-+117+%2B+36+=+0\"$
\n" ); document.write( " $\"117+-+117+=+0\"$
\n" ); document.write( " $\"b+=+2i\"$ should check also
\n" ); document.write( "(note that $\"+i%5E4+=+1\"$ ) \n" ); document.write( "

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