Question

[Măm Măm]

Khai triển các hằng đẳng thức sau:

\(a,\left(2x-1\right)\left(4x^2+2x+1\right)\)

\(b,\left(x+2y+z\right)\left(x+2y-z\right)\)

Answer 1

[Komorebi]

a) \(\left(2x-1\right)\left(4x^2+2x+1\right)=8x^3-1\)

b) \(\left(x+2y+z\right)\left(x+2y-z\right)=\left(x+2y\right)^2-z^2\)

Answer 2

[Hải Ngân]

a) \(\left(2x-1\right)\left(4x^2+2x+1\right)=\left(2x\right)^3-1^3=8x^3-1\)

b) \(\left(x+2y+z\right)\left(x+2y-z\right)=\left(x+2y\right)^2-z^2.\)