A shipping company charges $6 to ship a package that weighs up to 1 pound and $2 for each additional pound or portion of a pound. Which of the following equation represents this situation?

A) f (x) = 6 + 2 (x - 1), where x > 0

B) f (x) = 6 + 2 (x + 1), where x > 0

Hmm, lets experiment

for 1 lb it should be $6

A. f (1) = 6+2 (1-1) = 6+2 (0) = 6, yep

B. f (1) = 6+2 (1+1) = 6+2 (2) = 6+4=10, nope

A is answer

Let x be the weight of the package in pounds

We know that if x = 1, the cost is $6

Using this in the given two equations,

6 = 6 + 2 ((1) - 1)

6 = 6 which is true

OR

6 = 6 + 2 ((1) + 1)

6 = 10 which is not true

Therefore, the correct equation is the first one. Also, x must be greater than 0 because if we plug in 0 to our correct equation, option A, then the price is less than the minimum that needs to be paid (minimum price when shipping 1 lb)