Linear Equations and Word Problems

Which of the following situations could be descried by the equation y= -25x + 120

• There are 120 people in the football stadium, and 25 more are entering each hour.

• A plumber charges $25 for a house call and $120 per hour.

• A teacher has 120 students. Her third period has 25 students

• There are 120 gallons of water in a tank. It releases water at a rate of 25 gallons per minute

A landscaping company bought a total of 25 plants and trees. The total cost of the plants and trees was $964. Each plant costs $12, while each tree costs $95. Which set of equations correctly represents this situation?

• p + t = 25

  12p + 95t = 964

• p + t = 964

  95p + 12t = 25

• 107pt = 964

  12p + 95t = 107

• 25p = 964

Looking at the equation x + 5 = 3x -1 tells me that I can perform which step first...

• Subtract 5 from both sides of the equals sign

• Add x to both sides of the equals sign

• Add 3x to both sides of the equals sign

• Subtract 1 from both sides of the equals sign

Which equation best represents the relationship between x and y in the table shown?

• y= 5x+5

• y=1/5x+5

• y=15x+5

• y=10x+5

Find the intial value

• 0

• 3

• 4

• 5

Find the rate of change.

• -2 minutes per gallon

• -20 minutes per gallon

• -2 gallons per minute

• -20 gallons per minute

A music app charges $2 to download the app plus $1.29 per song downloaded. Write a linear equation to find the total cost to download 30 songs.

• y=1.29x + 2

• y=1.29 + 2x

• 30 = 1.29x + 2

• y = 1.29(30) + 2

A group of mountain climbers begin an expedition with 250 pounds of food. The plan to eat a total of 12 pounds of food per day. Write a linear equation to find the number of days their food will last.

• y = 250 + 12x

• y = 250 - 12x

• 0 = 250 - 12x

• y = 250 - 12(0)

Write the linear inequality in standard form for this situation: Ms. Savva is ordering pizzas and breadsticks for a school party and has a budget of no more than $81. An order of breadsticks costs $7 and a pizza costs $13. 

• 7x + 13y < 81

• 7x + 13y ≥ 81

• 7x + 13y ≤ 81

• 7x + 13y > 81

Write the linear inequality in standard form for this situation: The CRHS science department can spend no more than $2700 on textbooks this year. The department needs to buy both Biology text books, which cost $57 each, and Chemistry textbooks, which cost $72 each.

• 57x + 72y ≥ 2700

• 57x + 72y > 2700

• 57x + 72y < 2700

• 57x + 72y ≤ 2700