Đa thức này ko phân tích thành nhân tử được

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

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

\(x^3+27x+\left(x+3\right)\left(x-9\right)\)
⇒\(x^3+27x+x^2-6x-27\)
⇒\(x^3+x^2+21x-27\)
Chịu

Sửa đề: \(x^3+27+\left(x+3\right)\left(x-9\right)\)

\(=\left(x^3+27\right)+\left(x+3\right)\left(x-9\right)\)

\(=\left(x+3\right)\left(x^2-3x+9\right)+\left(x+3\right)\left(x-9\right)\)

\(=\left(x+3\right)\left(x^2-3x+9+x-9\right)\)

\(=\left(x+3\right)\left(x^2-2x\right)=x\cdot\left(x-2\right)\left(x+3\right)\)

`#3107.101107`

`x(y - 1) + 3(y - 1)`

`= (x + 3)(y - 1)`

x(y-1)+3(y-1)

=(y-1)(x+3)

Giải thích: đặt y-1 ra làm chung .... đa thức còn x+3

a: \(3x^4-4x^3+1\)

\(=3x^4-3x^3-x^3+1\)

\(=3x^3\left(x-1\right)-\left(x-1\right)\left(x^2+x+1\right)\)

\(=\left(x-1\right)\left(3x^3-x^2-x-1\right)\)

b: \(x^3-19x-30\)

\(=x^3-4x-15x-30\)

\(=x\left(x-2\right)\left(x+2\right)-15\left(x+2\right)\)

\(=\left(x+2\right)\left(x^2-2x-15\right)\)

\(=\left(x+2\right)\cdot\left(x-5\right)\left(x+3\right)\)

\(x-y+\sqrt{xy^2}-\sqrt{y^3}\)

\(=\left(x-y\right)+\left(y\sqrt{x}-y\sqrt{y}\right)\)

\(=\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}+\sqrt{y}\right)+y\left(\sqrt{x}-\sqrt{y}\right)\)

\(=\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}+\sqrt{y}+y\right)\)

\(x-\sqrt{x}-2\\ =x+\sqrt{x}-2\sqrt{x}-2\\ =\sqrt{x}\left(\sqrt{x}+1\right)-2\left(\sqrt{x}+1\right)\\ =\left(\sqrt{x}+1\right)\left(\sqrt{x}-2\right)\)