Question

nanette installed a security system in her office for $150. the monthly monitoring fee is $30. so far, nanette has spent $420 for her security system. for how many months has she had the service?

Answer 1

9 months.

Explanation:

Well we subtract the one time fee of $150 from $420

420-150=270

Now we need to divide $270 by $30, the price she pays every month.

270÷30=9

She has had the service for 9 months.