Hello there. To solve this question, we need to remember some properties on lines.
First, let's isolate the y variable on both line equations
L1: y = 9/4 - x/2
L2: y = 4 - 2x
Now, remember that when you have two lines with equations y = ax + b and y = cx + d, they are parallel if and only if a = c and perpendicular iff a = -1/c.
If none of these conditions are met, then they're neither parallel nor perpendicular.
As we can see, the coefficients a and c are respectively -1/2 and -2.
Notice that -1/2 is not equal to -2, thus the lines are not parallel.
Also, -1/2 is not equal to -1/(-2) = 1/2. Thus, the lines are not perpendicular.
With this, we can conclude the lines are neither parallel nor perpendicular.