Question

Tính:

1, \(\left(a^2-1\right)\left(a^2-a+1\right)\left(a^2+a+1\right)\)\

2,\(\left(a^6-3a^3+9\right)\left(a^3+3\right)\)

Answer 1

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

Answer 2

\(2,\left(x^6-3x^2+9\right)\left(x^3+3\right)=\left(x^3+3\right)\left[\left(x^3\right)^2-3x^2+3^2\right]=x^9+3^3\)

Answer 3

xl mk lm nhầm , mk sửa lại nha \(\left(a^6-3a^3+9\right)\left(a^3+3\right)=\left(a^3+3\right)\left[\left(a^3\right)^2-3a^3+3^2\right]=a^9+27\)