Question 626866
Use Special Products and factoring: {{{(x-y)(x^2+xy+y^2) = x^3 - y^3}}}
let x = {{{a/2}}} and y = {{{2/3}}}
{{{(a/2 - 2/3)(a^2/4 + a/3 + 4/9)}}} = {{{(a/2)^3 - (2/3)^3 }}}
                                          = {{{highlight(a^3/8 - 8/27)}}}