You have been evaluating cell phone providers. Double Mint Mobile has a $100 startup fee and costs $30 per month for a cell phone plan. BT&T has a $20 startup fee and costs
$50 per month for a similar cell phone plan.
After how many months will both cell phone plans cost the same?

4 months

Step-by-step explanation:

Let

x = number of months

Double Mint Mobile = 100 + 30x

BT&T = 20 + 50x

After how many months will both cell phone plans cost the same?

Equate the cost of both phone plans

Double Mint Mobile = BT&T

100 + 30x = 20 + 50x

100 - 20 = 50x - 30x

80 = 20x

x = 80/20

x = 4 months

Number of months = 4 months

For this case we have that by definition, the volume of a cube is given by:

Where:

l: It's the side of the cube

According to the statement we have:

Substituting we have:

Thus, the volume of the cube is

The volume of the cube is