Linear Functions in Real Life

Given the function below, what is the dependent variable?

• The height of the plant (x-axis)

• The height of the plant (y-axis)

• Number of weeks (x-axis)

• Number of weeks (y-axis)

What does H(5) =18 mean in the context of the problem?

• The height of the plant after 5 weeks is 18 inches

• The height of the plant after 18 weeks is 5 inches

• The height of the plant is 5 inches after 18 weeks

• The height of the plant is dependent on the week it was planted

Given this table of the function f(x), what is the independent variable?

• Number of weeks

• Pounds of soil

Given this table of the function f(x), find x when f(x)=15 and explain what it means in context.

• f(1) = 15 means the farmer increases his soli by 15%

• f(15) = 1 means after 15 weeks the farmer has 1 pound of soil.

• f(1) = 15 means after 1 week the farmer has 16 pounds of soil.

• f(1) = 15 means after 1 week the farmer has 15 pounds of soil.

The math club goes to an amusement park. Student tickets cost $10 each. The bus costs $28. This is expressed as f(x) = 10x + 28. Find f(10) and explain what it means.

• f(10) = 100; It costs $4100 for 10 students to go on the trip.

• f(10) = 128; It costs $128 for 10 students can go on the trip.

• f(128) = 10; It costs $10 for 128 students to go on the trip.

• f(10) = 128; It costs $10 for 128 students can go on the trip.

Suppose you are saving for a new skateboard. You currently have $10 that you put in an envelope to save. Each week you put $5 in that envelope. If this were to be written as a function, how would 10 and 5 be represented?

• 10 would be the slope; 5 would be the y-intercept

• 10 would be the y-intercept; 5 would be the slope

• 15 would be the y-intercept

• 15 would be the slope

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

What is the rate of change for the following graph?

• 80

• 20

• 40

• 160

Which statement matches the graph?

• Taylor can write 6 words per minute

• Taylor can write 25 words per minute

• Taylor can write 50 words per minute

• Taylor can write 150 words per minute

The table represents a used car salesman's monthly salary including commission made on the sale of cars.  What is the y-intercept and what does it represent?

• The y-intercept is $850/car and it represents the commission per car sold.

• The y-intercept is $1500/car and it represents the commission per car sold.

• The y-intercept is $1500 and it represents the monthly salary before commission.

• The y-intercept is $2775 and it represents the monthly salary before commission.