Unit 3: Lesson 2 : Graphs of Proportional Relationships

I can graph a proportional relationship from an equation.

I can tell when two graphs are of the same proportional relationship even if the scales are different.

 $y=\ 1\frac{3}{4}x$  

 $y=\ 1.75x$  

 $y=\frac{7}{4}x$  

I will give you 12 proportional relationship graphs.

Write the equation for each graph. Some graphs may have the same equation. You can group the ones that will have the same equation.

 $A;\ y=\ 0.25x$  

 $B,E,H;\ y=3x$  

 $C,D,G,K;\ y=3.5x$  

 $I,L;\ y=\frac{4}{3}x$  

 $F,J;\ y=\frac{5}{2}x$  

Answer the following questions and say which graph you used to find your answer.

Q1: After 30 seconds, which tank has the most water? 

Q2: At approximately what times do both tanks have the same amount of water? 

Q3: At approximately what times do both tanks contain 1 liter of water? 20 liters? At approximately what times do both tanks contain 1 liter of water? 20 liters? 

A1: Using the first graph, Tank A has more water after 30 seconds.

A2: Using the second graph, at approximately 64 minutes both tanks have the same amount of water.

A3: Using the first graph, Tank A has a liter of water after 1 minute. Tank B has a liter of water after 2 minutes. Using the second graph, Tank A has 20 liters of water at around 36 minutes while Tank B has 20 liters of water at 40 minutes. Using the first graph, Tank A has a liter of water after 1 minute. Tank B has a liter of water after 2 minutes. Using the second graph, Tank A has 20 liters of water at around 36 minutes while Tank B has 20 liters of water at 40 minutes.