Question 95390
3a^3 + 3ab^2 + 2a^2b + 2b^3 
There is no common factor for the four terms.
But factoring the 1st two terms and the last 
two terms separately you get:
3a(a^2+b^2)+2b(a^2+b^2)
Factor out the common factor of a^2+b^2 to get:
(a^2+b^2)(3a+2b)
======================