Set 14: Quadratic Equations

Choice A is correct. Choice A is the correct answer. We want $a^2 + b^2$. 1. Sum ($a+b$) = 4. 2. Product ($ab$) = 2. 3. Identity: $a^2 + b^2 = (a+b)^2 - 2 ab$. 4. Substitute: $4^2 - 2(2) = 16 - 4 = 12$. Choice B is incorrect because it is $(a+b)^2$. Choice C is incorrect. Choice D is incorrect.