x(a + 1) - 2y(a + 1)
-5x(a + c) + 2y(a + c)
8a^2 - 12ab
a(n + 2) + (n + 2)
abc + abc^2
15m^3 + 20m^2
(a + 1)(x - 2y)
(a + c)(2y - 5x)
abc (1 + c)
4a(2a - 3b)
5m^2 (3m + 4)
(n + 2)(a + 1)
