For this case, what you should know is that the equations that represent an inverse variation are those that could not form a straight line, for example.
We have then: Equation 1: pv = 13 Rewriting: p = 13 / v P and v are represent an inverse variation. Equation 2: z = (2 / x) z and x are represent an inverse variation. Answer: equations represented inverse variation are: pv = 13 z = (2 / x)