Representations of Functions Practice

Write a function rule for the statement:

The output is four times the input.

• y = 4 + x

• x = 4 + y

• y = 4x

• x = 4y

Write a function rule for the statement:

The output is eight less than the input.

• y = x - 8

• x = y - 8

• y = 8 - x

• x = 8 - y

Find the value of y when x = 12.

 $y\ =\ \frac{x}{3}$  

Find the value of y when x = 2.

 $y\ =\ 5x\ +\ 9$  

You set up a hot chocolate stand at a football game. The cost of your supplies is $75. You charge $0.50 for each cup of hot chocolate.

Write a function that represents the profit P for selling c cups of hot chocolate.

• P = 50c

• P = 0.50c

• P = 75 - 0.50c

• P = 75 + 0.05c

P = 75 - 0.50c

You will break even (profit = 0) when the cost of your supplies equals your income. How many cups of hot chocolate must you sell to break even?