Question

Phân tích đa thức thành nhân tử

a) y^2( x^2-y)-zx-zy

b) 3x (x+1)^2-5x^2(x-1)+7(x+1)

c)25(x-y)^2-16(x+y)^2

Answer 1

a: Sửa đề: \(y^2\left(x^2-y^2\right)-xz-yz\)

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

\(=\left(x+y\right)\left(xy^2-y^3-z\right)\)

c: \(25\left(x-y\right)^2-16\left(x+y\right)^2\)

\(=\left(5x-5y\right)^2-\left(4x+4y\right)^2\)

\(=\left(5x-5y-4x-4y\right)\left(5x-5y+4x+4y\right)\)

\(=\left(x-9y\right)\cdot\left(9x-y\right)\)