Lines $y=(3a+2)x-2$ and $2y=(a-4)x+2$ are parallel. What is the value of $a$?
To find the value of $a$, I need to use the fact that parallel lines have equal slopes. The slope of the first line is $3a+2$, and the slope of the second line is $\frac{a-4}{2}$. Setting these slopes equal, I get the equation $3a+2=\frac{a-4}{2}$. To solve for $a$, I can cross-multiply and simplify: $6a+4=a-4$, $5a=-8$, $a=-\frac{8}{5}$. 