Bai 1 : Tính
a) \(\left(3x^n+1-2x^n\right)4x^2\)
b) 2\(\left(x^{2n}+2x^ny^n+y^{2n}\right)-y^n\left(4x^n+2y^n\right)\)
c)\(\left(x^{2n}+x^ny^n+y^{2n}\right)\left(x^n-y^n\right)\left(x^{3n}+y^{3n}\right)\)
d)\(4^{n+1}-3.4^n\)
[Các bạn giúp mình nha ! Plz ]
a: \(=12x^{n+2}+4x^2-8x^{n+2}\)
\(=4x^{n+2}+4x^2\)
b: \(=2x^{2n}+4x^ny^n+2y^{2n}-4x^ny^n-2y^{2n}\)
\(=2x^{2n}\)
c: \(=\left(x^{3n}-y^{3n}\right)\left(x^{3n}+y^{3n}\right)\)
\(=x^{6n}-y^{6n}\)
d: \(=4^n\cdot4-3\cdot4^n=4^n\)