Question

The rate of change is constant in the graph. Find the rate of change. Explain what therate of change means for the situation.

Answer 1

In general, given two points on a line, use the formula below to find its slope

`\begin{gathered} (x_1,y_1),(x_2,y_2) \\ \Rightarrow slope=(y_2-y_1)/(x_2-x_1) \end{gathered}`

In our case, the graph goes through (0,400) and (12,0); then, calculating its slope

`\begin{gathered} (0,400),(12,0) \\ \Rightarrow slope=(400-0)/(0-12)=-(400)/(12)=-(100)/(3) \end{gathered}`

Thus, the slope is -100/3. It means that the value drops $100 every 3 years. The answer is option B