Chapter 12.2, Problem 55STP

To determine

To find: Which of the following is an inverse variation.

Answer to Problem 55STP

Option A

Explanation of Solution

Taking Option A

From the given data in option A

We get

  $\begin{array}{l}\left(x_1,y_1\right)=\left(2,50\right)\\ \left(x_2,y_2\right)=\left(5,20\right)\end{array}$

Use a proportion that relates the values

  $\frac{y_1}{x_2}=\frac{y_2}{x_1}$ Indirect variation

On substituting values

We get

  $\begin{array}{l}\frac{y_1}{x_2}=\frac{y_2}{x_1}\\ \Rightarrow \frac{50}{5}=\frac{20}{2}\\ \Rightarrow 10=10\end{array}$

As $10=10$

Therefore,

Option A represents an inverse variation.

A is the correct option.