Question 870316
{{{625x^4-16=(25x^2-4)(25x^2+4)=(5x-2)(5x+2)(25x^2+4)}}};
The quadratic factor will have two complex zeros, each with imaginary part.
{{{25x^2=-4}}}
{{{5*x=-2i}}} and {{{5x=2i}}}
{{{x=-(2/5)i}}} and {{{x=(2/5)i}}}
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The other zeros, from the linear factors are {{{-(2/5)}}} and {{{(2/5)}}}.


All multiplicities are 1.