3x - 6 => 3(x - 2)
3x - 30m + 1 => 3(x - 10m) + 1
-10 - 30m => -10(1 + 3m)
21mn + 7n => 7n(3m + 1)
x^2 - 2x => x(x - 2)
4.
(- 9a²b) * (7ac⁴) = - 63a³bc⁴
Ответ: - 63а³bc⁴
5.
(4a²c²)³ * (2bc)²/16abc - a⁵bc⁷ = (4³a⁶c⁶) * (4²b²c²)/16abc - a⁵bc⁷ =
= 16 * 16 *a⁶b²c⁸/16abc - a⁵bc⁷ = 16a⁵bc⁷ - a⁵bc⁷ = 15a⁵bc⁷
Ответ: 15a⁵bc⁷
=-72a²-16ab+9ab+2b²-45a²-15ab+18ab+6b²
=-117a²-4ab+8b²