Question

Phân tích đa thức sau thành nhân tử

a) \(\dfrac{1}{8}\)x³\(-\)\(\dfrac{3}{4}\)x²+\(\dfrac{3}{2}\)x\(-\)1

b) x⁴+2015x²+2014x+2015

Answer 1

a)Đặt \(A=\dfrac{1}{8}x^3-\dfrac{3}{4}x^2+\dfrac{3}{2}x-1\)

\(A=\dfrac{1}{8}\left(x^3-6x^2+12x-8\right)\)

\(A=\dfrac{1}{8}\left(x-2\right)^3\)

Answer 2

b,\(x^4+2015x^2+2014x+2015=x^4+2015x^2+2015x-x+2015=x\left(x^3-1\right)+2015\left(X^2+x+1\right)=x\left(x-1\right)\left(x^2+x+1\right)+2015\left(x^2+x+1\right)=\left(x^2+x+1\right)\left(x^2-x+2015\right)\)