1. Tables and Functions
#31

2. Vocabulary
A function is a rule that relates two quantities so that each input value corresponds exactly to one output value.

3. Example 1
Write an equation for a function that gives the values in the table. Use the equation to find the value of y for the indicated value of x. 16 13 10 7 4 y 3 2 1 x

4. FYI
You can write equations for functions that are described in words.

5. Example 2
Write an equation for the function. Tell what each variable you use represents.
The height of a painting is 7 times its width.

6. Example 3
Write an equation for the function. Tell what each variable you use represents.
A large pie costs $2 more than a small pie.

7. Real-world Application
The school band tracked the number of tickets sold and the total amount of money received. They sold each ticket for the same price. They received $60 for 20 tickets, $66 for 22 tickets, and $81 for 27 tickets. Write an equation for the function.