Set 13: Quadratic Equations

Choice A is correct. Choice A is the correct answer. 1. Take the square root: $2x + 1 = \pm 5$. 2. Set up two cases: * $2x + 1 = 5 \Rightarrow 2 x = 4 \Rightarrow x = 2$ * $2x + 1 = -5 \Rightarrow 2 x = -6 \Rightarrow x = -3$ Choice B is incorrect because of sign errors. Choice C is incorrect because it solved $x + 1 = 25/2$ incorrectly. Choice D is incorrect because it misses the negative case properly.