(а-6)(а²+2)-(4а+1)(а-3) при а=3

(а-6)(а²+2)-(4а+1)(а-3)==a³+2a-6a²-12-(4a²-12a+a-3)==a³+2a-6a²-12-(4a²-11a-3)==a³+2a-6a²-12-4a²+11a+3==a³+13a-10a²-9.при а=3====>>>3³+13*3-10*3²-9==27+39-10*9-9==27+39-90-9=-33

(а-6)(а²+2)-(4а+1)(а-3)=(a^3+2a-6a^2-12)-(4a^2-12a+a-3)=a^3+2a-6a^2-12-4a^2+12a-a-3=a^3-10a^2+13a-15=27-90+39-15= -39