Vocabulary
What do we call the rate of change in a proportional relationship?
Constant of proportionality
Is the relationship proportional if the equation is y=6x?
Yes
Find the slope of y=7x
7
Write an equation with slope 5 that passes through the origin.
y=5x
A job pays $12 per hour. What is the slope?
12
What does the slope represent on a distance–time graph?
Speed
Is y=4x+3y = 4x + 3y=4x+3 proportional? Why or why not?
No, it does not pass through the origin
Find the slope between points (0,0) and (4, 20).
5
A job pays $9 per hour. Write an equation.
y=9x
A car travels 180 miles in 3 hours. What does the slope represent?
Specify the units
60 miles per hour
What is slope also called when comparing two quantities?
Unit Rate
A table shows y increases by 5 every time x increases by 1 and includes (0,0). Proportional or not?
Proportional
A graph rises 12 units and runs 3 units. What is the slope?
4
Slope is 4 and y = 12 when x = 3. Write the equation.
y=4x
A graph shows slope = 4. What does this mean in a cost-per-item situation?
Each item costs $4
What point must every proportional relationship pass through?
Origin or (0,0)
A graph is a straight line but does NOT pass through the origin. Is it proportional?
No
A cyclist travels 45 miles in 3 hours. What is the slope of the graph?
15 miles per hour
A taxi charges $3 per mile and no starting fee. Equation?
y=3x
Which situation is proportional:
A) $5 per hour plus $10 bonus
B) $5 per hour
B
What does a positive slope tell you about a relationship?
As x increases, y increases
Which represents a proportional relationship:
A) cost = 2x + 5
B) distance = 3x
B
Slope is y/x.
If y = 18 when x = 3, what is the slope?
6
Write an equation for a proportional relationship with unit rate 2.5
y=2.5x
A student graphs y=4x but starts at (0,2). What is incorrect?
The y-intercept should be 0
Should start at (0,0)