Bài 3:
a: \(x^3-x=x\left(x-1\right)\left(x+1\right)\)
b: \(x^3-4xy^2=x\left(x^2-4y^2\right)=x\left(x-2y\right)\left(x+2y\right)\)
c: \(25-4x^2=\left(5-2x\right)\left(5+2x\right)\)
d: \(x^3-2x^2+x=x\left(x^2-2x+1\right)=x\left(x-1\right)^2\)
e: \(4x^2y-y=y\left(4x^2-1\right)=y\left(2x-1\right)\left(2x+1\right)\)
f: \(9-\left(x+y\right)^2=\left(3-x-y\right)\left(3+x+y\right)\)