Question 1164256
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    {{{a^3 + 3a^2 + 3a + 2}}} = re-grouping = {{{(a^3 + 3a^2 + 3a + 1)}}} + 1 = {{{(a+1)^3}}} + 1 = {{{((a+1) + 1)*((a+1)^2 - (a+1)*1 + 1)}}}


and you can simplify it further and complete.



On the way, I used these identities


    {{{x^3 + 3x^2 + 3x + 1}}} = {{{(x+1)^3}}};

    {{{x^3 + 1}}} = {{{(x+1)*(x^2 - x + 1)}}},


which every student must know from his (or her) Algebra class.
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