Linear/Exponential Functions

Write a rule:  A plumber charges $50 for a house call plus $12 per hour for labor.

• y = 50 x + 12
• y = 50 + 12 x
• y = 62 x
• x = 50 + 12y

Write a rule: The cost of renting a car cost $65 for deposit and $37.50 per day.

• x = 65 + 37.50 y
• y = 65 x + 37.50
• y= 92.50x
• y= 37.50 x + 65

Write a rule :  Mojo has joined a weight loss program.  His weight is 225 lbs and he is losing weight at a rate of 3 lbs per week.

• y = 222 x
• y = 225 + 3 x
• y = 225 - 3x
• y=225x - 3

A plane is flying into Omaha Eppley Airfield.  The plane's height and minutes  above the ground are related to each other in this function; h = 30000 - 2000m.  What do the numbers represent?

• 30000 is start height, 2000 is the feet the plane descends per minute.
• 30000 is the start speed of the plane, 2000 is how much the speed slows down.
• 2000 is the starting speed of plane, 30000 is how much speed increases.
• 2000 is the starting height, 30000 is the feet the plane descends per minute.

Describe what each part of the rule represents: 
The amount Nick has left and the number of days are related by the rule m = 50 - 5d.

• Nick starts with -5 dollars and spends $50 each day.
• Nick starts with $5 and earns $50 each day.
• Nick starts with $50 and earns $5 each day.
• Nick starts with $50 and spends $5 each day.

Write a rule for the following table:
x:      -2     -1     0     1     2     3
-------------------------------
y:       -3     0      3     6     9     12

• y = 3x -1
• y = 3 + 3x
• y = -3x -2
• y = x + 3

Is the graph pictured a function? (hint: vertical line test)

• Yes
• No

• Function
• Not a Function

Is the graph pictured a function? (hint: vertical line test)

• Yes
• No

• Function
• Not a Function