Question

Khai triển

\(\left(2a^2+1\right)^3\)

Answer 1

\(\left(2a^2+1\right)^3=\left(2a^2+1\right)\left(2a^2+1\right)\left(2a^2+1\right)\\ =\left(4a^4+4a^2+1\right)\left(2a^2+1\right)\\ =8a^6+8a^4+2a^2+4a^4+4a^2+1\\ =8a^6+12a^4+6a^2+1\)

Answer 2

\(\left(2a^2+1\right)^3=8a^6+12.a^4+6a^2+1\)