Question

(3a-1)(9a^2+3a+1)-(3a+1)(9a^2-3a+1)+2a+2

Answer 1

\(\left(3a-1\right)\left(9a^2+3a+1\right)-\left(3a+1\right)\left(9a^2-3a+1\right)+2a+2\)

\(=27a^3-1-\left(27a^3+1\right)+2a+2=27a^3-1-27a^3-1+2a+2\)

\(=-2+2a+2=2a\)