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