Question

CELL PHONES Many cell phone plans have an option to include more than one phone. The function for the monthly cost of cell phone service from a wireless company is f(x) = 25x + 200, where x is the number of phones on the plan. Find and interpret f(3) and f(5).

Answer 1

f(3)=275, f(5)=325

Explanation:

We just plug in 3 and 5 into the equation:

We get f(x) = 25x + 200

f(3) = 25*3 + 200

=75+200

=275

Interpretation: if there are three cell phones on the plan, then the total monthly cost is 275.

for f(5):

f(5) = 25*5 + 200

=125+200

=325

Interpretation: if there are five cell phones on the plan, then the total monthly cost is 325.