14 - 14m^2 = 14(1 - m^2) = 14(1 - m)(1 + m)
20a^3 - 20a^2 + 5a = 5a(4a^2 - 4a + 1) = 5a(2a - 1)(2a - 1)
14 - 14m^2 = 14(1 - m^2) = 14(1 - m)(1 + m)
20a^3 - 20a^2 + 5a = 5a(4a^2 - 4a + 1) = 5a(2a - 1)(2a - 1)