Question

[Phan Duong Quynh Anh]

Phan tich da thuc thanh nhan tu:

x^3 - x + 3x^2y + 3xy^2 + y^3 - y

x^2 + 5x - 6

Answer 1

[Minh Triều]

x^3 - x + 3x^2y + 3xy^2 + y^3 - y

=x³+y³+3x²y+3xy²-x-y

=(x+y)(x²-xy+y²)+3xy(x+y)-(x+y)

=(x+y)(x²-xy+y²+3xy-1)

=(x+y)(x²+2xy+y²-1)

=(x+y)[(x+y)²-1]

=(x+y)(x+y-1)(x+y+1)

x^2 + 5x - 6

=x²-x+6x-6

=x.(x-1)+6.(x-1)

=(x-1)(x+6)