Solve the Problem. -Suppose That a Sales Person Observes That If an Item

Multiple Choice

Solve the problem.
-Suppose that a sales person observes that if an item is priced at $7 per item then 11 items are sold. If 9 items are sold for $9 per item then find a linear function f(x) = mx + b whose input is the price
Of the item in dollars and whose output is the number of items sold.

A) f(x) = x + 18
B) f(x) = -x + 18
C) f(x) = -x + 4
D) f(x) = x + 4