posted by Kiri .
A delivery service charges a base price for an overnight delivery of a package plus an extra charge for each pound the package weighs. A customer is billed $22.85 for shipping a 3-pound package and $40 for shipping a 10-pound package.
1.) Write an equation that gives the total cost of shipping a package as a function of the weight of the package.
2.)Find the cost of shipping a 15-pound package.
I don't get ANY of this.