Question

Phân tích đa thức thành nhân tử

A = x-y-3(\(\sqrt{x}+\sqrt{y}\))

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

Answer 1

a) Có sai đề ko ạ?

b) Đặt \(\sqrt{x}=a;\sqrt{y}=b\) (để cho nó đỡ rối mắt:v)

\(B=a^3-b^3+a^2b-ab^2\)

\(=\left(a-b\right)\left(a^2+ab+b^2\right)+ab\left(a-b\right)\)

\(=\left(a-b\right)\left(a+b\right)^2=\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}+\sqrt{y}\right)^2\)

True?

Answer 2

A = \(x-y-3\left(\sqrt{x}+\sqrt{y}\right)=\left(\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}+\sqrt{y}\right)-3\left(\sqrt{x}+\sqrt{y}\right)=\left(\sqrt{x}+\sqrt{y}\right)\left(\sqrt{x}-\sqrt{y}-3\right)\)