What is the value of x if x/2+13 = 4?

Undo the operations in reverse order. Multiply both sides of $\frac{\frac{x}{2} + 1}{3} = 4$ by 3 to get $\frac{x}{2} + 1 = 12$. Subtract 1: $\frac{x}{2} = 11$. Multiply by 2: $x = 22$, choice A. Check: $\frac{22}{2} + 1 = 12$, and $\frac{12}{3} = 4$. The other choices fail the check. Choice B (10) gives $\frac{6}{3} = 2$, which comes from forgetting the final multiplication by 2 after subtracting 1 and stopping at 11 and then subtracting again. Choice C (6) gives $\frac{4}{3}$. Choice D (34) gives 6, which comes from adding 1 instead of subtracting it.