Answer:
$25.00
Step-by-step explanation:
A key ingredient of success at working with word problems is defining units correctly. In this case, note that the cost corresponds to 2 years of service. Also, the problem asks for the one-month fee. Then, a good start would be saying: OK, the cost of 24 months of service was $685, including the installation fee. Since this fee is a one-time cost, not a monthly cost, we need to subtract it from our total cost. Then the cost of the service minus the installation fee could be written as:
24x = 685 - 85
24 months of service, at x cost per month, is equal to 685 minus 85.
If you solve this equation, you will find the value of x:
24x = 600
x = 600 ÷ 24
x = 25
The monthly fee is $25. In 2 years you paid 24 times 25, or $600. Add to this amount the installation fee of $85 and you will arrive to your total cost, which includes the installation fee.
