Mn giúp em bài này với ạ phân tích đa thức thành nhân tử nhóm hạng tử ạ

1) x^2 + 3x - x - 3 = (x^2 + 2x) + (-3) = x(x + 2) - 3 = (x + 2)(x - 1)

4) xy + y - 2x - 2 = (xy - 2x) + (y - 2) = x(y - 2) + 1(y - 2) = (y - 2)(x + 1)

7) x^2 + xy - xz - yz = x(x + y) - z(x + y) = (x + y)(x - z)

10) xy - 3x - y^2 + 3y = (xy - y^2) - (3x - 3y) = y(x - y) - 3(x - y) = (x - y)(y - 3)

13) x^2 + 5xy + x + 5y = x^2 + 5xy + 5y + x = x(x + 5y) + 5y = (x + 5)(x + y)

16) x^2 - 2x + 2y - xy = (x^2 - 2x) + (2y - xy) = x(x - 2) + y(2 - x) = (x - 2)(x + y)

19) 2xy + 3z + 6y + xz = (2xy + 6y) + (3z + xz) = 2y(x + 3) + z(3 + x) = (x + 3)(2y + z)

22) x^2 + 3xy - 5x - 15y = (x^2 + 3xy) - (5x + 15y) = x(x + 3y) - 5(x + 3y) = (x + 3y)(x - 5)

25) x^3 + 6x^2 + x + 6 = (x^3 + 6x^2) + (x + 6) = x^2(x + 6) + 1(x + 6) = (x + 6)(x^2 + 1)

28) x^2y - x^3 - 9y + 9x = (x^2y - x^3) + (9x - 9y) = x^2(y - x) + 9(x - y) = (y - x)(x^2 - 9)

31) 4x^3 - 4x^2 - 9x + 9 = 4x^2(x - 1) - 9(x - 1) = (x - 1)(4x^2 - 9) = (x - 1)(2x - 3)(2x + 3)