Đáp án:
a) x ² -xy -8x + 8y = (x ²-xy) - (8x-8y)
= x(x-y) -8(x-y)
= (x-8) (x-y)
b) x ² - 16y^4 = (x - 4y ²) (x + 4y ²)
c) x³ - 16x = x(x ² -16)
= x(x-4)(x+4)
d) (2x - 3) ² - (x- 5) ² = 4x ² - 12x + 9 - x ² - 10x - 25
= 3x ² - 22x -16
e) (2x -1 )² - 9(x + 2)² = 4x² - 4x +1- 9( x² + 4x + 4)
= 4x² - 4x +1- 9x² -36x -36
= -5x² -40x -35
g) 7x² -7xy -4x + 4y = (7x ²-7xy) - (4x-4y)
= 7x(x-y) -4(x-y)
= (7x-4) (x-y)
Chúc bạn học tốt nhaz. ²