Simplify (a+b) ^3 + (a-b) ^3 + 6a (a^2-b^2)

8a^3.

Step-by-step explanation:

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

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

(a+b) ^3 + (a-b) ^3=2a^3+6ab^2

According to the question

(a+b) ^3 + (a-b) ^3+6a (a^2-b^2)

Put in the value

=2a^3+6ab^2 + 6a^3-6ab^2

=8a^3