Можешь ли ты сократить дробь $\frac{21a^3 - 6a^2b}{12ab - 42a^2}$?

Конечно, давай сократим дроби! а) $\frac{21a^3 - 6a^2b}{12ab - 42a^2} = \frac{3a^2(7a - 2b)}{6a(2b - 7a)} = \frac{a(7a - 2b)}{2(2b - 7a)} = -\frac{a}{2}$. б) $\frac{6m^3 + 3mn^2}{2m^3n + mn^3} = \frac{3m(2m^2 + n^2)}{mn(2m^2 + n^2)} = \frac{3}{n}$. в) $\frac{x^2 - 2mx + 3x - 6m}{x^2 + 2mx + 3x + 6m} = \frac{x(x - 2m) + 3(x - 2m)}{x(x + 2m) + 3(x + 2m)} = \frac{(x - 2m)(x + 3)}{(x + 2m)(x + 3)} = \frac{x - 2m}{x + 2m}$. г) $\frac{8ab + 2a - 20b - 5}{4ab - 8b^2 + a - 2b} = \frac{2a(4b + 1) - 5(4b + 1)}{4b(a - 2b) + 1(a - 2b)} = \frac{(4b + 1)(2a - 5)}{(a - 2b)(4b + 1)} = \frac{2a - 5}{a - 2b}$. д) $\frac{16a^2 - 8ab + b^2}{16a^2 - b^2} = \frac{(4a - b)^2}{(4a - b)(4a + b)} = \frac{4a - b}{4a + b}$. е) $\frac{9x^2 - 25y^2}{9x^2 + 30xy + 25y^2} = \frac{(3x - 5y)(3x + 5y)}{(3x + 5y)^2} = \frac{3x - 5y}{3x + 5y}$. ж) $\frac{a^2 - 3a}{a^2 + 3a - 18} = \frac{a(a - 3)}{(a + 6)(a - 3)} = \frac{a}{a + 6}$. з) $\frac{4x^2 - 8x + 3}{4x^2 - 1} = \frac{(2x - 3)(2x - 1)}{(2x - 1)(2x + 1)} = \frac{2x - 3}{2x + 1}$. и) $\frac{m^2 + 4m - 5}{m^2 + 7m + 10} = \frac{(m + 5)(m - 1)}{(m + 5)(m + 2)} = \frac{m - 1}{m + 2}$