A balloon’s circumference decreases at a constant rate. The graph shows the balloon’s circumference over time.

What is the slope of the line that represents the situation?

Enter the slope as a decimal. @Hero @Directrix @zepdrix @iambatman @Nurali

Question

A balloon’s circumference decreases at a constant rate. The graph shows the balloon’s circumference over time.
 
What is the slope of the line that represents the situation? 
 
Enter the slope as a decimal. @Hero @Directrix @zepdrix @iambatman @Nurali

anonymous · Answer

http://static.k12.com/calms_media/media/1512000_1512500/1512349/1/e682f410896cc483335c976d46f50fd393bb1abb/MS_IMC-140516-100013.jpg

anonymous · Answer

help pls help

zepdrix · Answer

Hmm so they gave us two points that we can easily use :)
$\Large\rm (x_1,y_1)=(5,5)$ and $\Large\rm (x_2,y_2)=(10,1)$.

Remember your slope formula?$$\Large\rm m=\frac{y_2-y_1}{x_2-x_1}$$

zepdrix · Answer

So to calculate our slope, we just plug the numbers into the correct slots!