B1
g) 2(x + y) - 5y(x + y)
= (x+y)(2-5y)
h) 2(x - y) + y(y - x)
= 2(x-y) - y(x-y)
= (x-y)(2-y)
e) x^2 - 6x
= x(x-6)
f) 4x - 6y
= 2(2x-3y)

Bài 2:
a) 2(x - 1)^2.(phân tích rồi)
b) y(x - y)^2 + xy(x - y).
= y(x - y)(x - y + x)
= y(x - y)(2x - y)
c) xy(x + y) - 2x - 2y.
=xy(x + y) - 2(x + y)
= (xy - 2)(x + y)
d) x(x + y)^2 - y( y + x)^2.
= (x - y)(x + y)^2

Bài 2.
e) (x + 1)^2 - (x + 1)
= (x + 1)(x + 1 - 1)
= x(x + 1)
f) x(x+ y)^2 + xy(x + y).
= x(x + y)(x + y + y)
= x(x + y)(x + 2y)
g) xy(x - y) - 2x + 2y.
= xy(x - y) - 2(x - y)
= (x - y)(xy - 2)
h) y(x - y)^2 + x(y - x)^2.
= y(x - y)^2 + x(x - y)^2
= (x - y)^2(x + y)

B1
a) x^2 - 2x = x(x - 2)
b) 3x - 6y = 3(x - 2y)
c) 5(x + 3y) - 15(x + 3y)
= (x + 3y)(5 - 15) = -10.(x + 3y)
d) 3(x - y) - 5(y - x) = 3(x - y) + 5(x - y)
= (x - y)(3 + 5) = 8(x - y)
g) 2(x + y) - 5y(x + y)
= (x+y)(2-5y)
h) 2(x - y) + y(y - x)
= 2(x - y) - y(x - y) = (x-y)(2-y)
e) x^2 - 6x = x(x - 6)
f) 4x - 6y = 2(2x - 3y)

Bài 2:
a) 2(x - 1)^2
b) y(x - y)^2 + xy(x - y).
= y(x - y)(x - y + x) = y(x - y)(2x - y)
c) xy(x + y) - 2x - 2y.
=xy(x + y) - 2(x + y) = (xy - 2)(x + y)
d) x(x + y)^2 - y( y + x)^2.
= (x - y)(x + y)^2
e) (x + 1)^2 - (x + 1)
= (x + 1)(x + 1 - 1) = x(x + 1)
f) x(x + y)^2 + xy(x + y).
= x(x + y)(x + y + y) = x(x + y)(x + 2y)
g) xy(x - y) - 2x + 2y.
= xy(x - y) - 2(x - y) = (x - y)(xy - 2)
h) y(x - y)^2 + x(y - x)^2.
= y(x - y)^2 + x(x - y)^2 = (x - y)^2(x + y)