Question 997649
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{{{9x^3-7x^2+441x-343}}} = {{{0}}}.


Group:


{{{9x^3-7x^2+441x-343}}} = {{{(9x^3 + 441x)}}} - {{{(7x^2 + 343)}}} = {{{9x*(x^2 + 49)}}} - {{{7*(x^2 + 49)}}} = {{{(9x - 7)*(x^2 + 49)}}}.


The roots are x = {{{7/9}}}, {{{7i}}} and {{{-7i}}}. 

The last two are complex numbers.