PETE C. answered • 02/05/20

BS in Math with minor in English with 30+ Years of Teaching Experience

**HOW MUCH MONEY WILL SHE HAVE WHEN HER GRANDMOTHER PAYS HER**

**FOR 20 LAPS?**

Let the number of **LAPS **be the **X **value of ordered pairs.

Let the **DOLLAR AMOUNT** be the **Y **value of the ordered pairs.

LAPS MONEY

(1, **1**)

(2, **3**)

(3, **5**)

(4, **7**)

Notice that the Y value above is always an ODD number.

The FUNCTION RULE applied to the X value, resulting in the ODD NUMBER Y value is:

**f(X) = 2X - 1.**

So, f(1) = (2 * 1) - 1 = 2 - 1 = 1

f(2) = (2 * 2) - 1 = 4 - 1 = 3

f(3) = (2 * 3) - 1 = 6 - 1 = 5

f(4) = (2 * 4) - 1 = 8 - 1 = 7

For 20 LAPS, X = 20, we use the above function.

f(20) = (2 * 20) - 1 = 39

**ANSWER: HER GRANDMOTHER GIVES HER $39 **

**Is this donation pattern an exponential function, linear function, or neither? **

f(X) is the same thing as the value of Y.

So, f(X) = 2X - 1 is the same as Y = 2X - 1.

Y = 2X - 1 IS A **LINEar EQUATION. (Lowercase "ar" for emphasis.)**

**Why?**

**Not exponential because of the FUNCTION RULE 2X-1.**

**An example of an EXPONENTIAL FUNCTION would be f(X) = X^2 + 5. **

**Hope this helps Jason.**