The formula m = (y2-y1) / (x2 - x1) can be used for a proportional and nonproportional relationships.
yes
What is the equation of a line when m = -3 and b = 5?
y = -3x+5
What is linear equation?
y = mx + b
What is the slope of this equation?
y= 3x + 5
m = 3
What is b in the equation y=150x + 40
b = 40
what makes the slope negative?
A slope is a negative when the graph is going 'down' / when the rise is negative
Bob has $150 in his savings account and saves $40 per month.
y=40x + 150
What is a Y intercept?
The y-intercept is the point where the graph intersects the y-axis.
find the slope
m = 4
What is the y intercept 
b = 0
what is the first step when you want to graph?
plot the y- intercept
Stephanie owes her mom $80 for a recent trip to the mall. She plans to payback $15 a month until it is paid back. Write an equation in slope-intercept form that relates the amount she owes, y, to the amount of months, x.
y = 15x + 80
What is the slope of a proportional line?
m = k = y/x
Find the slope
m=5/2
What is b? 
b = 3
What is the slope and intercept y = 5x
m = 5 b = 0
Jackson started with $800 in his savings account, but has to pay $30 a month for his electricity bill. Write an equation that relates his savings, y, to the amount of months, x.
y = -30x + 800
What is Slope?
Slope is a value that describes the steepness and direction of a line.
What is the line going through (0,5) and (4, -3) ?
m= - 8/4 = -2
What is b?
b = -1
What is the slope and intercept y = -9
m = 0 b = -9
Tickets to a baseball game cost $22 each and parking cost $10. What is the equation of the line that represents the cost of attending the game?
y = 22x + 10
what is the slope's formula?
m=(y2-y1)/(x2-x1)
What is the slope of this line?
(-5, 7) and (3, 4)
m= (4-7)/(3--5) = -3/8
What is the y-intercept of the line?
(-4, 6) (0, 2)
y-intercept when x=0 therefore y-intercept is 2