Question 1053168
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  {{{x^3-5x^2-25x+125}}} = (grouping !) = {{{(x^3-25x) - (5x^2 -125)}}} = 


= {{{x(x^2-25) - 5(x^2-25)}}} = {{{(x^2-25)*(x-5)}}} = {{{(x-5)^2*(x+5)}}}.


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