A phone company charges a flat fee of $100 for one phone installation plus $40 for each additional phone jack. How many phones could be installed flr $420? For this question, you will need to write the equation to model the problem and answer the question.

Respuesta :

The answer is 9 phones.

First you subtract the initial phone installation with $420.

420 - 100 = 320

Now divide: 320/40 = 8

8 plus the first phone phone eaquals 9.