If 3a^2 = b^2 ne 0, then the value of frac(a + b)^3 – (a – b)^3(a + b)^2 + (a –

If 3a^2 = b^2 ne 0, then the value of frac(a + b)^3 – (a – b)^3(a + b)^2 + (a – b)^2 is?