Answer:
f(x) = 2.25x + 5
Step-by-step explanation:
The cost from the weight in pounds of the box can be represented by 2.25x, since the charge is $2.25 per pound.
The flat fee of $5 can be represented in the function by adding 5 to 2.25x.
Put these together in function notation:
f(x) = 2.25x + 5
So, the equation is f(x) = 2.25x + 5