Question

The cost of using a parcel service is r dollars for the first 3 pounds and s dollars for each additional pound. which of the following expressions represents the cost, in dollars, of sending a parcel that weighs 9 pounds?

a) r+3s
b) r+6s
c) 3r+6s
d) 3r+9s
e) 9r+9s

Answer 1

The correct answer is: c) 3r + 6s

Explanation:

the first 3 pounds are always going to be r dollars, then every additional pound will be s dollars.

Since we have a package that weighs 9 pounds; 3 pounds will cost r dollars and 6 pounds wills cost s dollars.

example:

lets say that r = 10 and s = 5

the first 3 pounds will cost 10 dollars and then every pound after would be 5 dollars

so:

3(10) + 6(5)

This is just an example, since we don't know the actual values of r and s, we just use those variables.