Question 1079207
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<pre>
{{{3x^3 - 7x^2 + 12x - 28}}} = (apply grouping) = {{{(3x^3 + 12x)}}} - {{{(7x^2+28)}}} = {{{3x*(x^2+4)}}} - {{{7*(x^2+4)}}} = {{{(3x-7)*(x^2+4)}}}.


The real zero is x = {{{7/3}}}.


The two complex zeroes are x = 2i  and  x = - 2i.
</pre>

Solved.