# Math help

posted by
**Mr.Brain**
.

A gas station charges $2.19 per gallon of gas. Use function notation to describe the relationship between the total cost C(g) and the number of gallons purchased g.

C(g) = –2.19g

g = 2.19C(g)

C(g) = g + 2.19

C(g) = 2.19g

Please tell me the explination and the answer.