Question

The charge to ship a package from one town to another, C, is given below as a function of the weight of the object, w, in pounds.

C = $2.50 + $0.55w

If the shipping cost for Cathy's item was $7.29, what was its weight?
A.
18.7 pounds
B.
0.87 of a pound
C.
87 pounds
D.
8.7 pounds

Answer 1

D) 8.7lbs

Subtract $2.50 from the total cost, because that's a fixed number, then do more math and boom, just like magic, it's solved.

Answer 2

8.7 pounds

Explanation:

7.29 = 2.5 + 0.55 w

0.55 w = 7.29 - 2.5

0.55 w = 4.79

w = 4.79 / 0.55

w. 8.7