Question

Phân tích x⁴ +8x thành nhân tử

Answer 1

\(x^4+8x=x.\left(x^3+8\right)\)

\(=x.\left(x^3+2x^2-2x^2-4x+4x+8\right)\)

\(=x.\left[\left(x^3+2x^2\right)-\left(2x^2+4x\right)+\left(4x+8\right)\right]\)

\(=x.\left[x^2.\left(x+2\right)-2x.\left(x+2\right)+4.\left(x+2\right)\right]\)

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

Chúc bạn học tốt!!!

Answer 2

Bài này dễ mà em!

\(x^4+8x\\ =x\left(x^3+8\right)\\ =x\left(x+2\right)\left(x^2-2x+4\right)\)

Answer 3

Ta có:\(x^4+8x=x\left(x^3+8\right)=x\left(x^3+2^3\right)=x\left(x+2\right)\left(x^2-2x+4\right)\)