Answer
y varies inversely as x can be modeled by the equation $y\ =\ \frac{k}{x}$
Work Step by Step
The variable y varies inversely as x means $y\ \propto \ \frac{1}{x}$ , which implies that when the variable x increases, y decreases or when x decreases, y increases.
Use the constant of proportionality k, to get $y\ =\ \frac{k}{x}$.
Hence, the variable y varies inversely as x can be written as $y\ =\ \frac{k}{x}$ , where k is called the constant of proportionality.
