**Решение:**
1) (1000m^3 - n^3 = (10m)^3 - n^3 = (10m - n)(100m^2 + 10mn + n^2))
2) (81a^3 - ab^2 = a(81a^2 - b^2) = a(9a - b)(9a + b))
3) (-8x^2 - 16xy - 8y^2 = -8(x^2 + 2xy + y^2) = -8(x + y)^2)
4) (5mn + 15m - 10n - 30 = 5m(n + 3) - 10(n + 3) = (5m - 10)(n + 3) = 5(m - 2)(n + 3))
5) (256 - b^4 = (16 - b^2)(16 + b^2) = (4 - b)(4 + b)(16 + b^2))