Graphing Proportional Relationships
Equations of Proportional Relationships
Identifying Proportional Relationships
Slope
Linear Equation
100
What is the ordered pair for the origin?
** Don't forget your parentheses around the ordered pair! **
(0,0)
100
Is this equation proportional? y= 3x
If so, what is the constant of proportionality? (K)
Yes
k=3
100
How do you find the constant of proportionality?
Y/X
100
What is the slope formula
y2-y1
______
x2-x1
100
What is the format of a linear equation?
y-mx+b
200
A relationship between two quantities that is changing at a CONSTANT rate is:
a. proportional
b. nonproportional
a. proportional
200
Is this equation proportional? If so what is the constant of proportionality? (K=)
y= 4x + 10
Not proportional
200
Is the graph a proportional relationship? Why?
NO
Does not go through the origin
200
How can you use a graph to find slope
- Count the rise over run between two coordinates on the graph
200
Label all of the parts of the linear equation
y=mx+b
m=slope
b=y intercept
300
What are the two rules to know if a graph is proportional?
1. The line is straight (to show a constant rate)
2. The line goes through the origin (0,0)
300
Is this equation proportional? If so what is the constant of proportionality? (K=)
y= ¾ x
proportional
k= 3/4
300
Is the table proportional?
No
300
Find the slope between the two points:
(3,5) (6,10)
5/3
300
Explain how to graph a linear equation
Start with the y-intercept and place a coordinate there
From that place, use the slope (rise/run) to find the second coordinate.
Continue that again to find the third coordinate.
Connect the coordinates
400
Is this graph proportional? Explain WHY.
Yes, it is a straight line that goes through the origin.
400
Using this graph, What is the equation? Write your constant of proportionality as a FRACTION. 
y= 1/6x
400
Is the table proportional?
Yes it is proportional
400
Find the slope between the two coordinates:
Simplify your answer
(-3, - 5) (2, -15)
-2/1
400
87
500
A recipe for lemonade is given by the equation y = 4x where x represents the cups of lemonade mix and y represents the cups of water.
If Tyler had 16 cups of lemonade mix, how many cups of water would he need for each recipe?
64 cups of water
500
Write an equation for the table given the table is proportional.
y = 3/2 x
or y = 1 1/2x
or y = 1.5x
500
How do you know if a table is proportional?
When you divide the y value with its x value, you get the same constant of proportionality in each row.