Writing Equations for Proportional Relationships

​Writing Equations of Proportional Relationships

​LET'S REVIEW

Multiple Choice

Does the graph represent a proportional relationship?

• Yes, it is proportional.

• No, it is NOT proportional.

Multiple Choice

Is the graph proportional or non-proportional?

• Proportional
• Non-Proportional

Multiple Choice

Is the graph proportional or non proportional?

• proportional
• non proportional

Multiple Choice

What is the formula for a proportional relationship?

• y=kx
• z=ykx
• y=ky

Multiple Choice

What is the constant of proportionality? 

• 10

• 5

​NEW INFORMATION

​Constant of Proportionality Equation

(Also known as UNIT RATE)​

​​y = k x

where "k" is the constant of proportionality​

​y = 3x

​3 is the C.O.P.

This is an example of a graph with a line that is proportional. The constant of proportionality is 5. You can find the constant of proportionality by dividing one of the water values (y) by one of the time values (x).

​

THEREFORE

​

The equation for this graph is:

y=5x​

Constant of Proportionality

• All proportional relationships have constant ratio, which is called the unit rate.

• ​

• ​In the table to the right, the unit rate can be found by dividing the distance by the time.

​TIME TO PRACTICE

Multiple Choice

Find the constant of proportionality on this table of values.

• k=3

• k=1

• k=0

• k=4

Multiple Choice

In the equation y = 14x, what is the constant of proportionality?

• y
• x
• 14
• y=14

Multiple Choice

What does k represent in the equation y = kx?

• constant of proportionality
• the equation

Multiple Choice

Which equation matches the graph?

• y = 7x
• y = 42x
• y = 6x
• y = 2x

Multiple Choice

What is the constant of proportionality? 

• 4
• 8
• 1/8

Multiple Choice

What is the constant of proportionality for this table?

• 1/9
• 9
• 8

Multiple Choice

Determine the constant of proportionality for the table. Express your answer as y = kx

• x = 1/2y

• y = 2x

• k = x

Multiple Choice

Is the given table a proportional relationship? If so, what is the constant?

• Yes; 3
• Yes; 5
• No

Independent Work:

• Write Equations of Proportional Relationships from tables

• Write Equations of Proportional Relationships from graphs

​Some text here about the topic of discussion.

Independent Work