Answer
\sqrt[y] xBoth of those molecules are non-polar due to the arrangement of the atoms within them, allowing them to pass through the hydrophobic/non-polar center of the membrane which blocks polar or charged molecules from moving through without assistance.
Work Step by Step
\frac{x}{y}This question is asking you to see that the hydrophobic interior of membranes is what allows them to act as barriers to the movement of most molecules, providing the ability to keep inside and outside compartments different.