Variables and Patterns Study Guide

Express the relationship as an equation: the total amount of money earned (t) if the cost of lemonade is $2.00 per cup (c)

• tc = 4

• t = c

• t = 2c

Express the relationship as an equation: the balance on my $25 gift card (b) for any number of $3.50 chicken sandwiches that I purchase. (n)

• b = 3.30 + 25n

• b = 25n

• b = 25 - 3.50n

Express the relationship as an equation: The total cost (c) for a gym with a sign-up fee of $50 and a $12.50 monthly charge. (m)

• c = 50m

• c = 50 + 12.50m

• c = 50 + 12.50

Express this relationship as an equation:

If the price (p) for a slice of plain pizza is $1.25 plus an additional $0.15 for pepperoni, how much would it cost for some number (n) of students to buy a piece of pepperoni pizza?

• p = n (1.25 + 0.15)

• p = 1.25n

• p = n + 1.40

What is the independent variable in all of these graphs?

• money

• height

• time

Which story would match this graph?

• Bike riders increased at a steady rate, took a break for lunch, then rode back home as a steady rate.

• The bikers rode quickly at a steady rate until they met their destination and stopped.

• The riders had wind blowing against them making their strip take longer.

Gilbert’s Bubble Gum Emporium sells packs of gum for $0.75 per pack. Which a table shows the costs for different amounts of packs of gum.

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What would the independent variable be if you graphed the situation:

Gilbert’s Bubble Gum Emporium sells packs of gum for $0.75 per pack.

• Independent variable = location of store

• Independent variable = total cost

• Independent variable = number of packs purchased

What would the dependent variable be if you graphed the situation:

Gilbert’s Bubble Gum Emporium sells packs of gum for $0.75 per pack.

• Dependent variable = Number of packs purchased

• Dependent variable = Total cost

• Dependent variable = Location of store sign

Gilbert also has a V.I.P. customer card that costs $2.00 to purchase. However, once a V.I.P. purchases the card, the cost of each pack of gum goes down to $0.50! John made a chart to represent this situation. Is he correct?

• Yes, John's chart is correct

• No, John's chart is not correct

• I'm not sure