-(a+2)³-(a-2)a=-(a³+6a²+12a+8)-a²+2a=-a³-6a²-12a-8-a²+2a=-a³-7a²-10a-8
-(a+2)^3-(a-2)a=-(a^3+6a^2+12a+8)-(a-2)a=-a^3-6a^2-12a-8-a^2+2a=-a^3-7a^2-10a-8
-(a+2)³-(a-2)a=-(a³+6a²+12a+8)-a²+2a=-a³-6a²-12a-8-a²+2a=-a³-7a²-10a-8
-(a+2)^3-(a-2)a=-(a^3+6a^2+12a+8)-(a-2)a=-a^3-6a^2-12a-8-a^2+2a=-a^3-7a^2-10a-8