Разложите на множители:
1) $3x^2 + 12xy$;
2) $10m^5 - 5m$;
3) $ab - ac + 7b - 7c$;
4) $6x - xy - 6y + y^2$;
5) $49b^2 - c^2$;
6) $p^2 + 12pk + 36k^2$;
7) $100a^4 - \frac{1}{9}b^2$;
8) $25a^2 - (a - 3)^2$.
$3x^2 + 12xy = 3x(x + 4y)$
$10m^5 - 5m = 5m(2m^4 - 1)$
$ab - ac + 7b - 7c = (ab - ac) + (7b - 7c) = a(b - c) + 7(b - c) = (b - c)(a + 7)$
$6x - xy - 6y + y^2 = (6x - 6y) - (xy - y^2) = 6(x - y) - y(x - y) = (x - y)(6 - y)$
$49b^2 - c^2 = (7b)^2 - c^2 = (7b - c)(7b + c)$
$p^2 + 12pk + 36k^2 = (p + 6k)^2$
$100a^4 - \frac{1}{9}b^2 = (10a^2)^2 - (\frac{1}{3}b)^2 = (10a^2 - \frac{1}{3}b)(10a^2 + \frac{1}{3}b)$
$25a^2 - (a - 3)^2 = (5a)^2 - (a - 3)^2 = (5a - a + 3)(5a + a - 3) = (4a + 3)(6a - 3)$
Пожауйста, оцените решение