Question

Phân tích  đa thức sau thành nhân tử .

 ab(b - a) - bc(b - c) - ac(c - a)

Answer 1

\(ab\left(b-a\right)-bc\left(b-c\right)-ac\left(c-a\right)\)

\(=ab\left[\left(b-c\right)+\left(c-a\right)\right]-bc\left(b-c\right)-ac\left(c-a\right)\)

\(=ab\left(b-c\right)+ab\left(c-a\right)-bc\left(b-c\right)-ac\left(c-a\right)\)

\(=\left[ab\left(b-c\right)-bc\left(b-c\right)\right]+\left[ab\left(c-a\right)-ac\left(c-a\right)\right]\)

\(=\left(b-c\right)\left(ab-bc\right)+\left(c-a\right)\left(ab-ac\right)\)

\(=-b\left(b-c\right)\left(c-a\right)+a\left(c-a\right)\left(b-c\right)\)

\(=\left(b-c\right)\left(c-a\right)\left(a-b\right)\)