phân tích đa thưc sau thành nhân tử
P= ab(a-b) + bc(b-c) + ca(c-a)
P= ab(a-b)+bc(b-c)+ca(c-a)
= a^2b-ab^2+bc(b-c)+c^2a-ca^2
= (a^2b-ca^2)-(ab^2-c^2a)+bc(b-c)
= a^2(b-c)-a(b^2-c^2)+bc(b-c)
= a^2(b-c)-a(b-c)(b+c)+bc(b-c)
= (b-c)[a^2-a(b+c)+bc]
= (b-c)(a^2-ab-ac+bc)
= (b-c)[(a^2-ac)-(ab-bc)]
= (b-c)[a(a-c)-b(a-c)]
= (b-c)(a-b)(a-c)