5. Decide whether or not each equation represents a proportional relationship.
a. Volume measured in cups (c) vs, the same volume measured in ounces (z) :
c={1/}{8} z
b. Area of a square (A) vs. the side length of the square (s): A=s²
c. Perimeter of an equilateral triangle (P) vs. the side length of the triangle (s):
3 s=P
d. Length (L) vs. width (w) for a rectangle whose area is 60 square units: L={60}/{w}