Identify Linear Functions

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

If I join the gym for a start up fee of $40 and monthly fee of $10, what are appropriate input values? (Equation: Y=40+10x)

• -4, -3, -2, -1, 0.....

• $10, $20, $30, $40......

• 0, 1, 2, 3.....

• only 1, 2, 3, and 4

If I join the gym for a start up fee of $40 and monthly fee of $10, what are appropriate outputs? (Equation: Y=40+10x)

• -4, -3, -2, -1, 0.....

• $10, $20, $30, $40......

• 0, 1, 2, 3.....

• $40, $50, $60.....

In the equation, y = mx + b, the letter b is the ___________.

• y-intercept

• x-intercept

• slope

• rate of change

What is the slope of the equation?
y = -3x + 4

• -3

• 3

• 4

• -4

Which is the graph of y= -x + 2?

• A

• B

• C

• D

What type of slope does the graph have?

• Zero

• Undefined

• Negative

• Positive

Is this graph a function or not a function? 

• Function

• Not a Function

Bob has $150 in his savings account and saves $40 per month. Which function models his savings?

• y = 150 + 40

• y = 40x + 150

• y = 150x + 40

A golf course charges $15 to rent golf clubs and charges $25 per round to play.  Write an equation to represent the total cost, T, for one player.

• T = 15 + 25r

• T = 15g + 25r

• T = 40 r

• T = 15r + 25