Use Vieta's formula for x² + px + q = 0. For this form, the sum of the roots is -p and the product of the roots is q. The given roots are 6 and -4, so their sum is 6 + -4 = 2. Since sum = -p, we have -p = 2, which gives p = -2. The product 6×-4 = -24 also matches the constant term, so the roots are consistent. Therefore the correct answer is -2.