Interpreting Slope and Initial Value

Which of the following situations could be described 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 candle is originally 12 inches tall and burns a constant rate of 2 inches per hour. Write a formula for the height of the candle remaining.

• y = 2x + 12

• y = -2x + 12

• y = 12x - 2

• y = 12x + 2

My water bottle started with 32 ounces of water in it and I drank 8 ounces per hour. Write a formula for the amount of water remaining.

• y = 8x + 32

• y = -8x + 32

• y = 8x - 32

• y = 32x + 8

The equation y = -6x + 40 represents a full tub of water draining each minute. Interpret the meaning of the slope.

• The tub loses 6 gallons of water each minute.

• The total amount of water left in the tub after x minutes of draining.

• There was initially 40 gallons of water in the tub.

• The number of minutes the tub has been draining for.

The equation y = -6x + 40 represents a full tub of water draining each minute. Interpret the meaning of the y-values.

• The tub loses 6 gallons of water each minute.

• The total amount of water left in the tub after x minutes of draining.

• There was initially 40 gallons of water in the tub.

• The number of minutes the tub has been draining for.

The equation y = -6x + 40 represents a full tub of water draining each minute. Interpret the meaning of the y-intercept.

• The tub loses 6 gallons of water each minute.

• The total amount of water left in the tub after x minutes of draining.

• There was initially 40 gallons of water in the tub.

• The number of minutes the tub has been draining for.

The equation y = -6x + 40 represents a full tub of water draining each minute. Interpret the meaning of the x-values.

• The tub loses 6 gallons of water each minute.

• The total amount of water left in the tub after x minutes of draining.

• There was initially 40 gallons of water in the tub.

• The number of minutes the tub has been draining for.

The graph shows the weight of a bucket as it is filled with sand. What is the weight of the empty bucket?

• 0 pounds

• 1 pound

• 2 pounds

• 6 pounds

What does the slope represent in this situation?

• The sloth runs 1 feet in 3 minutes

• The sloth runs 3 feet in 1 minute

• The sloth runs fast

• The sloth runs 6 feet in 1 minute

Which of the following is another meaning of y-intercept?

• location

• initial value

• total

• constant rate