A2. The lines with equations $(m+2) x-2 y+1=0$ and $\frac{x}{2}+\frac{y}{4}=1$, are parallel. What is $m$?
(A) -6
(B) $-\frac{1}{2}$
(C) -2
(D) 0

(E) The lines are not parallel for any value of $m$.
A2. Two lines are parallel if they have the same slope. The first one has a slope of $\frac{m+2}{2}$. We convert the second equation to the explicit form $y=-2 x+4$, from which we read the slope -2. We equate both slopes: $\frac{m+2}{2}=-2$. The solution to the equation is $m=-6$.