3. the speedy jet ski rental company charges an insurance fee and an hourly rental rate. the total cost is…

3. the speedy jet ski rental company charges an insurance fee and an hourly rental rate. the total cost is modeled by the function $r(x)=30 + 40x$. based on this model, which statements are true? i. $r(x)$ represents the total cost. ii. $x$ is the number of hours rented. iii. $40$ is the insurance fee. iv. $30$ is the hourly rental rate. 1) i, only 2) i and ii, only 3) i, iii, and iv, only 4) i, ii, iii, and iv

3. the speedy jet ski rental company charges an insurance fee and an hourly rental rate. the total cost is modeled by the function $r(x)=30 + 40x$. based on this model, which statements are true? i. $r(x)$ represents the total cost. ii. $x$ is the number of hours rented. iii. $40$ is the insurance fee. iv. $30$ is the hourly rental rate. 1) i, only 2) i and ii, only 3) i, iii, and iv, only 4) i, ii, iii, and iv

Answer

Explanation:

Step1: Analyze the function meaning

The function $R(x)=30 + 40x$ is a linear - cost function. In a cost - function of the form $y=a+bx$, $y$ represents the total cost. Here, $R(x)$ is the total cost of jet - ski rental, so statement I is true.

Step2: Determine the meaning of $x$

The variable $x$ is multiplied by the hourly rate. In the context of a rental cost function, $x$ represents the number of hours rented, so statement II is true.

Step3: Identify the insurance fee and hourly rate

In the linear function $R(x)=30 + 40x$, the constant term $30$ is the fixed cost (insurance fee in this case) and the coefficient of $x$ ($40$) is the hourly rental rate. So statements III and IV are false.

Answer:

  1. I and II, only