Question

Phân tích đa thức thành nhân tử:

a) x³ +8y³

b) x³ - 2x² - x + 2

c) 25 - 16x²

Answer 1

\(a,x^3+8y^3=\left(x+2y\right)\left(x^2-2xy+4y^2\right)\\ v,x^3-2x^2-x+2=\left(x^3-2x^2\right)-\left(x-2\right)=x^2\left(x-2\right)-\left(x-2\right)=\left(x-2\right)\left(x^2-1\right)=\left(x-1\right)\left(x+1\right)\left(x-2\right)\\ c,25-16x^2=\left(5-4x\right)\left(5+4x\right)\)

Answer 2

\(a,=\left(x+2y\right)\left(x^2-2xy+4y^2\right)\\ b,=x^2\left(x-2\right)-\left(x-2\right)\\ =\left(x-2\right)\left(x^2-1\right)=\left(x-1\right)\left(x-2\right)\left(x+2\right)\\ c,=\left(5-4x\right)\left(5+4x\right)\)

Answer 3

c: =(5-4x)(5+4x)

Answer 4

a. x³ + 8y³
= x³ + (2y)³
= (x+2y) ( x² - 2xy + 4y²)

Answer 5

\(a,=\left(x+2y\right)\left(x^2-2xy+4y^2\right)\)

\(b,=x^2\left(x-2\right)-\left(x-2\right)\)

\(=\left(x-2\right)\left(x^2-1\right)=\left(x-1\right)\left(x-2\right)\left(x+2\right)\)

\(c,=\left(5-4x\right)\left(5+4x\right)\)