The length of the rectangle is = 72 cm
The width of the rectangle is = 56 cm
Area of the rectangle is = 
= 
cm²
As given, the other rectangle has the same area as this one, but its width is 21 cm.
Let the length here be = x
Hence, length is 192 cm.
We can see that as width decreases, the length increases if area is constant and when length decreases then width increases if area is constant.
So, in the new rectangle,constant of variation=k is given by,
or 
Hence, the constant of variation is 
$3,005.06 is the answer for the question
Answer:
C) Commensalism has no effect on the species, while parasitism has a negative effect.
Explanation:
Commensalism and parasitism are both forms of species interaction.
Commensalism:
Commensalism refers to an ecological relationship between two species where one species benefits from the other but the other is neither harmed nor benefited. For example, remoras are little fish that attach to sharks and other larger fish. Remoras benefit in terms of protection, transport and food. They feed off scraps attached to the shark's mouth and teeth. However, the shark neither benefits nor suffers from this interaction.
Parasitism:
Parasitism is a relationship between a host and a parasite where the parasite benefits at the expense of the host. the parasite attains benefits while harming the host. For example, ticks and fleas that infest dogs. The ticks attain nutrients from the host's blood and in turn, weaken and harm the host.
