A(a+2)(a-2)-(a-3)( a^{2} +3a+9)

Question

A(a+2)(a-2)-(a-3)( a^{2} +3a+9)

Answer 1

A(a+2)(a-2)-(a-3)(a²+3a+9)=a(a²-4)-(a³-27)=a³-4a-a³+27=27-4a;