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). f(3)=$, which is the cost of a cell phone plan with phones for month; f(5)=$, which is the cost of a cell phone plan with phones for month.

Explanation:

Step1: Substitute x = 3 into the function

Substitute \(x = 3\) into \(f(x)=25x + 200\). So \(f(3)=25\times3+200\).

Step2: Calculate f(3)

\(f(3)=75 + 200=275\). It represents the cost of a cell - phone plan with 3 phones for a month.

Step3: Substitute x = 5 into the function

Substitute \(x = 5\) into \(f(x)=25x + 200\). So \(f(5)=25\times5+200\).

Step4: Calculate f(5)

\(f(5)=125+200 = 325\). It represents the cost of a cell - phone plan with 5 phones for a month.

Answer:

\(f(3)=\$275\), which is the cost of a cell phone plan with 3 phones for a month; \(f(5)=\$325\), which is the cost of a cell phone plan with 5 phones for a month.