Question

(3a^2+3ab+3b^2)/(4a+4b) * (2a^2-2b^2)/(9a^3-9b^3)

Answer 1

(3a^2+3ab+3b^2)/(4a+4b) * (2a^2-2b^2)/(9a^3-9b^3)=
3(a^2+ab+b^2)*2(a-b)(a+b)/(4(a+b)*9(a^3-b^3))=1/6