Question

a store offers packing and mailing services to customers. the cost of shipping a box is a combination of a flat packing fee of $5 and an amount based on the weight in pounds of the box, $2.25 per pound. which equation represents the shipping cost as a function of x, the weight in pounds?

$f(x) = 5x + 2.25$

$f(x) = 2.25x - 5$

$f(x) = 5x - 2.25$

$f(x) = 2.25x + 5$

Explanation:

Step1: Identify fixed and variable costs

The flat packing fee is $5 (fixed, doesn't depend on weight). The cost per pound is $2.25, so for \( x \) pounds, the weight - based cost is \( 2.25x \).

Step2: Form the function

Total shipping cost \( f(x) \) is the sum of the fixed fee and the weight - based cost. So \( f(x)=2.25x + 5 \).

Answer:

\( f(x)=2.25x + 5 \) (the fourth option: \( f(x)=2.25x + 5 \))