(x - 4)(ax² - 1)

(ax² - 1)4

(4 - ax²)

(x - ax²)(1 - 4)

(2c - 7d)(4c² + 14cd + 49d²)

(2c - 8c³)343d

(8c³ - 2c)(7d + 49)

343 - 8c

(x - y)(4 + 3x)

(x - y)(3x + y + 4)

(3x + y)4

(x - y)4

2(2x - y)(2x + y)

2(2x - y)(2x + y)(4x² + y²)

4

2x

(10a - 15b)(10a + 15b)

(15a - 10b)

0

(10a + 10b) 15b

(c - d)(8c + d + 5)

(8c - d)

(d + 5 - c)(c - d)

(8 - c)

(x - 6)(ax² - 1)

(1 - ax²)x

(x - ax²)

(x - 6)

(x - 7)(x - 8)

(x + 7)(x - 8)

(x + 7)(x + 8)

(x - 8)

(x - 2)(bx² - 1)

(x - 1) bx²

(bx² - x) x²

(1 - bx²)2

(2q + 4p)64p³

64p³ + 8q³

(4p + 2q)(16p² - 8pq + 4q²)

None of these