Question

+Phân tích đa thức thành nhân tử:

\(l,x^3+y^3+21x+21y\)

Answer 1

`x^3+y^3+21x+21y`

`=(x+y)(x^2-xy+y^2)+21(x+y)`

`=(x+y)(x^2-xy+y^2+21)`

Answer 2

\(x^3+y^3+21x+21y\)

\(=\left(x+y\right)\left(x^2-xy+y^2\right)+21\left(x+y\right)\)

\(=\left(x+y\right)\left(x^2-xy+y^2+21\right)\)

Answer 3

\(l,x^3+y^3+21x+21y\\=(x^3+y^3)+(21x+21y)\\=(x+y)(x^2-xy+y^2)+21(x+y)\\=(x+y)(x^2-xy+y^2+21)\)

#\(Toru\)