You can
put this solution on YOUR website!b^4+13b^2+36=0
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b^4 + 9b^2 + 4b^2 + 36 = 0
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b^2(b^2+9) + 4(b^2+9) = 0
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(b^2+9)(b^2+4) = 0
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(b+3i)(b-3i)(b+2i)(b-2i) = 0
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b = 3i or b = -3i or b = 2i or b = -2i
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Cheers,
Stan H.
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