Grade 7 Algebra: Identify Variables & Graph Linear Functions

A store sells pencils for $0.50 each. Write an equation to represent the total cost (C) of buying x pencils. What are the variables and constants in your equation?

• C = 0.50x; Variables: x (number of pencils), Constants: C (total cost), 0.50 (cost per pencil)

• C = 1.00x; Variables: x (number of pencils), Constants: C (total cost), 1.00 (cost per pencil)

• C = x + 0.50; Variables: C (total cost), x (number of pencils), Constants: 0.50 (additional fee)

• C = 0.25x; Variables: x (number of pencils), Constants: C (total cost), 0.25 (cost per pencil)

Maria is saving money to buy a new bike that costs $150. If she saves $15 each week, write a linear equation to represent her savings over time. Identify the variables and constants.

• S = 20t

• S = 15t

• S = 15t + 50

• S = 10t

A car rental company charges a flat fee of $20 plus $0.15 per mile driven. Write an equation for the total cost (T) of renting a car for m miles. What do the variables and constants represent?

• T = 0.15 + 20m

• T = 20m + 0.15

• T = 20 + 0.15m

• T = 20 - 0.15m

A gardener is planting flowers in rows. If each row has 5 flowers and there are r rows, write an equation for the total number of flowers (F). Identify the variables and constants in your equation.

• F = 5 - r

• F = r + 5

• F = 5 * r

• F = 5 / r

A school is organizing a field trip. The cost per student is $30, and there are s students attending. Write a linear equation for the total cost (C) of the trip. What are the variables and constants?

• C = 30 + s; Variables: C (total cost), s (number of students); Constant: 30 (cost per student)

• C = s/30; Variables: C (total cost), s (number of students); Constant: 30 (cost per student)

• C = 30s + 10; Variables: C (total cost), s (number of students); Constant: 10 (additional fee)

• C = 30s; Variables: C (total cost), s (number of students); Constant: 30 (cost per student)

Tom is collecting baseball cards. He starts with 10 cards and collects 3 more each week. Write an equation to represent the total number of cards (C) he has after w weeks. Identify the variables and constants.

• C = 10 - 3w

• C = 3w + 5

• C = 10 + 3w

• C = 10 + w

A bike shop sells bikes for $200 each. If they sell b bikes in a month, write an equation for the total revenue (R) from bike sales. What do the variables and constants represent?

• R = 200b + 50

• R = 100b

• R = 200 + b

• R = 200b

A recipe requires 2 cups of flour for every batch of cookies. If you want to make b batches, write an equation for the total amount of flour (F) needed. Identify the variables and constants in your equation.

• F = 4b

• F = b/2

• F = 2b + 1

• F = 2b

A movie theater charges $10 per ticket. If t tickets are sold, write an equation for the total revenue (R) from ticket sales. What are the variables and constants?

• R = t + 10

• R = 10 * t, where R is total revenue, t is the number of tickets sold, and 10 is the price per ticket.

• R = 10 - t

• R = 10 / t

A train travels at a speed of 60 miles per hour. Write an equation to represent the distance (D) traveled after h hours. Identify the variables and constants in your equation.

• D = 60h + 10

• D = 60 + h

• D = 60h

• D = 30h