Proportional Relationships and Equations from Graphs

Determine the slope and y-intercept from the following equation:   y = 3/2x + 3

• slope: 5   y-intercept:  (0,3) 

• slope: 3/2   y-intercept:  (0,3) 

• slope:  4  y-intercept:  (0,3/2)

• slope: 1/5   y-intercept:  (0,5) 

Write the equation of the line.

• y = -2/3x + 4

• y = 2/3x + 4

• y = 3/2x + 4

• y = -3/2x + 4

Does the equation show a proportional relationship?

• Yes

• No

These two lines are graphs of nonproportional relationships. What makes them nonproportional?

• They are not straight

• They are not linear

• They do not go through the origin

• They do not show a constant rate of change

What does 'b" represent in y=mx+b

• y-intercept

• change in y

• change in x

• constant rate of change

Steve started with $250 and spent $25 per week. Chelsea started with $30 and saved $30 per week.

Which two equations represent these situations?

• y = 250 - 25x

• y = 30 + 30x

• y = 250x + 25

• y = 30x - 30

Does this equation represent a proportional relationship?

• Yes

• No

Is the graph proportional or non proportional?

• proportional

• non proportional

Which best describes the equation?
y = 75x

• Proportional

• Nonproportional

Which of the equations below is proportional?

• y = 6x

• y = 3x + 2

• y = 2x + 4

• y = -2x -1