5.1 Classwork Weds

Suppose that the water level of a river is 34 feet and that it is receding at a rate of 0.5 foot per day. Write an equation to represent the given situation.

• y = -0.5x + 34

• y = -34x + 0.5

• y - 34 = 0.5(x - 1)

• 34x - 0.5y = 33.5

1) A plumber charges $25 for a service call plus $50 per hour of service. Write an equation for the given situation.

• y = 50x + 25

• y = 25x + 50

• y - 50 = 1(x - 25)

• 25x + 50y = 75

1) A car is driving down from the top of a Colorado mountain. The elevation at the top of the mountain is 13,500 feet. Every minute of driving, the car’s elevation decreases by 150 feet. Write an equation to represent the given situation.

• y = 150x + 13,500

• y = -150x + 13,500

• y - 13,500 = -(x - 150)

• 150x + 13,500y = 13,750

The cost to rent a car at the Johnson Car Rental is $29 per day plus a $50 non-refundable insurance cost. Write an equation to represent the given situation.

• y = 29x + 50

• y = 50x + 29

• y - 50 = 1(x - 29)

• 29x + 50y = 79

The Joyner’s swimming pool currently has 30 inches of water in it. In the spring, Mr. Joyner will refill the swimming pool by adding water at a rate of 2 inches per hour. Write an equation to represent the given situation.

• y = -2x + 30

• y = 2x + 30

• y - 30 = 2(x - 0)

• -2x + 30y = 28

A train is 500 meters above ground and descends at the rate of 50 meters per minute. What is the y-intercepet?

• 50

• 500

• y = 10

• 5

Lisa saves $20 every week. If she already has $200 in her savings account. What is the slope/rate and what is the y-intercept?

• m = 200

  b = 20

• m = -20

  b = 200

• m = 20

  b = 200

• m = -200

  b = 20

What is a y-intercept?

• a vertical line

• the point where the line crosses the x-axis

• a horizontal line

• the point where the line crosses the y-axis

Write the equation of the line.

• y = -2/3x + 4
• y = 2/3x + 4
• y = 3/2x + 4
• y = -3/2x + 4

What is the slope in the equation y=2x + 3?

• 2
• 3
• 5
• Cannot be Determined