Разложить на множители:

1) - 4a^8b+12a^2b^3c 4) 12x^2+6y-2x^2y-y^2

2) - 20x^6y-35x^6 5) 16x^3-xy^2

3) 7xy-y+21x-3 6) a^3b-25ab^3

1)

-4a⁸b+12a²b³c=4a²b (3b²c-a⁶)

2)

-20x⁶y-35x⁶ = - 5x⁶ (4y-7)

3)

7xy-y+21x-3 = (7xy-y) + (21x-3) = y (7x-1) + 3 (7x-1) = (7x-1) (y+3)

4)

12x²+6y-2x²y-y² = (12x²+6y) - (2x²y+y²) = 6 (2x²+y) - y (2x²+y) = (2x²+y) (6-y)

5)

16x³-xy²=x (16x²-y²) = x (4x-y) (4x+y)

6)

a³b-25ab³=ab (a²-25b²) = a (a-5b) (a+5b)