If (x+2)(x-4) = x² + bx + c for all values of x, what is the value of b + c?

Expand with FOIL: $(x + 2)(x - 4) = x^2 - 4x + 2x - 8 = x^2 - 2x - 8$. Matching $x^2 + bx + c$ gives $b = -2$ and $c = -8$. The sum is $b + c = -10$, choice B. Choice A ($-6$) uses $c = -4$ or an arithmetic slip, such as $-2 + (-4)$. Choice C ($-8$) is only $c$. Choice D (10) drops both negative signs. The question asks for $b + c$, not either alone, so add the two coefficients and keep their signs.