a) \(x^2-2x-4y^2-4y=\left(x^2-4y^2\right)-\left(2x+4y\right)=\left(x-2y\right)\left(x+2y\right)-2\left(x+2y\right)\)
\(=\left(x+2y\right)\left(x-2y-2\right)\)
b) \(x^4+3x^3-4x-4=\left(x^4-4\right)+\left(2x^3-4x\right)=\left(x^2+2\right)\left(x^2-2\right)+2x\left(x^2-2\right)\)
\(=\left(x^2-2\right)\left(x^2+2+2x\right)\)
c) \(x^2\left(1-x\right)^2-4x-4x^2=x^2\left(x^2-2x+1\right)-4x-4x^2=x^4-2x^3+x^2-4x-4x^2\)
\(x^4-2x^3-3x^2-4x=x\left(x^3-2x^2-3x-4\right)\)
Có gì sai thì nói giùm nha vì đang vội
2)a)x^2-2x-4y^2-4y
=(x^2-4y^2)-(2x+4y)
=(x-2y)(x+2y)-2(x+2y)
=(x+2y)(x-2y-2)
b﴿ x^4 + 3x^3 − 4x − 4
=﴾x^4 − 4﴿ +﴾2x^3 − 4x﴿
=﴾x^2 + 2﴿﴾x^2 − 2﴿ + 2x﴾x^2 − 2﴿
=﴾x^2 -2)(x^2+2+2x)
c)x^2(1 − x)^2 − 4x − 4x^2
= x^2 (x^2 − 2x + 1) − 4x − 4x^2
= x^4 − 2x^3 + x^2 − 4x − 4x^2x^4 − 2x^3 − 3x^2 − 4x
= x (x^3 − 2x^2 − 3x − 4)