Question 1170217
Let's break down this problem step by step:

**1. Identify Variables**

* **x:** The number of books your friend sends.
* **y:** The total shipping fee (in dollars).

**2. Identify the Slope**

* The slope represents the rate of change of the shipping fee per book.
* In this case, the shipping fee increases by $2 for each book.
* Therefore, the slope (m) is 2.

**3. Identify the y-intercept (b)**

* The y-intercept represents the shipping fee when no books are sent (x = 0).
* Even if no books are sent, there's a $10 insurance fee.
* Therefore, the y-intercept (b) is 10.

**4. Write the Equation in Slope-Intercept Form**

* The slope-intercept form of a linear equation is y = mx + b.
* Substitute the values we found for m and b:
    * y = 2x + 10

**Summary**

* **Equation:** y = 2x + 10
* **x:** Number of books
* **y:** Total shipping fee (in dollars)