The answer is (a+2). Let's find factors of a^2 + 7a + 10. a^2 + 7a + 10 = a^2 + 5a + 2a + 10 = a * a + 5 * a + 2 * a + 2 * 5 = (a * a + 5 * a) + (2 * a + 2 * 5) = a * (a + 5) + 2 * (a + 5) = (a + 5) * (a + 2) = (a + 5)(a + 2). Therefore, a^2 + 7a + 10 = (a + 5)(a + 2). i hope i helped this is what i came up with