Let us start with the original equation:
\((2a-1)^3\)
Splitting it up, or making it easier, we should put it into:
\((2a-1)(2a-1)(2a-1)\)
Multiplying the first two,:
\((4a^2-2a-2a+1)(2a-1)\)
Simplifying and Mathifying:
\((4a^2-4a+1)(2a-1) \\ =(8a^3-4a^2-8a^2+4a+2a-1) \\ =(8a^3-12a^2+6a-1)\)
So in the end, the answer is:
(8a^3-12a^2+6a-1)
