Объяснение:
(5a-12)-((2a-1)(a²+2a-1)+3a² =(5a-12)-(2a³+4a²-2a-a²-2a+1)+3a²=
=5a-12-2a³-4a²+2a+a²+2a-1+3a²= -2a³+9a-13
Объяснение:
(5a-12)-((2a-1)(a²+2a-1)+3a² =(5a-12)-(2a³+4a²-2a-a²-2a+1)+3a²=
=5a-12-2a³-4a²+2a+a²+2a-1+3a²= -2a³+9a-13