Proportional Relationships
If a ladybug crawls 4cm in 2 seconds, how long does it take to crawl 12cm?
What is 6 seconds
What would you look for to identify a proportional relationship in a graph or a table?
SOS, Straight line, it starts at the origin (0,0), it has no y-intercept, same rate of change.
What is the slope of the equation: y = 25x - 100
What is 25
what does m and b stand for in the equation y = mx + b?
What is slope and y intercept
Allison says the graph is proportional because it goes through the origin. Is that a good enough reason?
No - graphs should have the origin AND be linear.
A person can drive 200 miles in 4 hours. What is the constant of proportionality?
50
The equation y = 2x tells how far a bug travels in cm, per second. How far did it crawl in 15 seconds?
What is 30 cm
I have $1000 in my bank account. $50 is added each month. What is the slope of this situation?
What is $50
Write an equation for the scenario:I start with no money in a savings account and save $10 per week
What is y = 10x
Combine like terms
2x+4-x+2
What is x+6
A family makes jam at home. They pack the jam at a rate of 80 jars per 5 hours.
What equation represents this?
y=16x
In Year 1 I have $600 in a savings account
In Year 3 I have $750 in a savings account
In Year 5 I have $900 in a savings account
In Year 7 I have $1050 in a savings account
How much do I add to the account each year?
What is $75
The rise is 2, the run is 3, but the line is going down.
What's the slope?
-2/3
Write an equation for the scenario: I owe my brother $100 and pay him back $5 per week
What is y = 5x - 100
Is x=5 a solution to the equation 15 = 3x - 2
What is no
15 = 3(5) - 2
15 = 15 - 2 (this is not true)
15 is not equal to 13
Siri's cell phone plan costs $24 per month. Draw a table that shows the costs of 1, 2, 3, and 4 months.
1 month $24
2 months $48
3 months $72
4 months $96
Deisy volunteered to help her teacher sell hot chocolate. In 1 minute she sells 3 cuts of hot chocolate. Which equation best represents y, the total number of hot chocolates Deisy sells in x minutes if she continues at this rate?
A. y = x + 3
B. x = 3y
C. x = y + 3
D. y = 3x
D. y = 3x
If y=-3x+5
What is the slope?
What is -3
Write an equation for the scenario: There was 6 inches of snow on the ground and 2 inches continues to fall each hour.
What is y = 2x+6
Which equation best represents a line where each value of y is 5 more than twice the value of x? Write it:
y = 2x + 5
A recipe says to use 2 cups of sugar to make 38 brownies. What is the constant of proportionality that relates the number of brownies made, y, to the number of cups of sugar used, x?
19 (38 divided by 2)
You want to ship math textbooks from Singapore. They cost $80 each, plus $30 shipping Write an equation to model the cost of the textbooks.
What is y = 80x+30
A road trip took 7 hours, and was 455 miles long.
What was the constant rate of change of the trip?
What is 65mph
Write an equation for the scenario: I have 150 baseball cards and sell 13 each week.
What is y = -13x + 150
What is the y-intercept?
y=2x+3
What is 3