y = mx

y = mx

Proportional Relationship

Direct variation

Slope Intro Review

 $slope\ =\ m\ =\frac{rise}{run\ }$  

Multiple Choice

Categorize the slope of the line

• Positive

• Negative

• Zero

• Undefined

Multiple Choice

Categorize the slope of the line

• Positive

• Negative

• Zero

• Undefined

Multiple Choice

Categorize the slope of the line

• Positive

• Negative

• Zero

• Undefined

Fill in the Blanks

Fill in the Blanks

Multiple Choice

What is the slope of the line?

• -2/3

• 2/3

• 3/2

• -3/2

Fill in the Blanks

Fill in the Blanks

Multiple Choice

What is the slope of the line?

• 3/1

• -3/1

• 1/3

• -1/3

Direct Variation

y = mx

If you can multiply the x values by the same constant and get the y value there is a direct variation. (This is also proportional)

Fill in the Blanks

Fill in the Blanks

Direct Variation Table

y directly varies in relation to x

y = mx
where m is a constant we multiply by x to get y

 $\frac{y}{x}=m\ \ \ \ \frac{6}{3}=2\ \ \ \ \ \frac{10}{5}=2\ \ \ \ m=2$  

Multiple Choice

Proportional or Non-Proportional?

• Proportional

• Non-Proportional

Multiple Choice

 $\frac{14}{7}\ =\ \frac{32}{8}$  

• True

• False

Multiple Choice

Does the table represent a proportional relationship?

• Yes.
• No.

Direct Variation

Graph

When data has a direct variation you get a straight line (linear) that goes through the origin.

Multiple Choice

The graph shown is:

• Proportional

• Not Proportional

Multiple Choice

Is the graph proportional or nonproportional?

• Proportional

• Non Proportional

Multiple Choice

Is the graph proportional or non proportional?

• proportional because it is a straight line and goes through the origin

• non proportional because it is not a straight line but goes through origin

• non proportional because it does not go through the origin but is a straight line

• non proportional because it does not go through the origin and is not a straight line

Equation

In the table to the right if we take y divided by x we get 5.

 $\frac{-5}{-1}\ =\ \frac{10}{2}\ =\ 5$  

therefore, m = 5
Our equation is
y = mx
y = 5x

Multiple Choice

What is the slope of the table?

• 1/4

• 4

• -6

• -4

Multiple Choice

What is the slope of the table?

• 1/2

• 2

• -2

• 3

Multiple Choice

What equation is represented by the table?

• y = 1/8x

• y = 8x

• y = x - 8

• y = x - 21

Multiple Choice

What equation is represented by the table?

• y = 1/3x

• y = 3x

• y = 10x

• y = x - 1/3

Multiple Choice

Find the slope

• -3/4
• 4/3
• 3/4
• -4/3

Multiple Choice

Find the slope

• 4/5
• 5/4
• -5/4
• -4/5