(a+b)^3=(a+b)^3=a^3+3a^2b+3ab^2+b^3

a^3+b^3=(a+b)(a^2-ab+b^2)

(n m stands for the m power of n)

Solution: Because a+b=3

So (a+b) 3 = a 3+3a 2b+3ab 2+b 3 = 3 3 = 27.

And because a 2b+ab 2 =-30.

So A3+B3 = (a+b) (A2-AB+B2) =117.

So a 2-ab+b 2 = 39.

So the original formula =39+ 1 1=50.