the first planhas a $16 monthly fee and charges an additional $.08 for each min. of calls. the second plan charges $10. fee and charges an addition $.13 for each min. for how many min. of calls will the cost be equal?

16 + .08x = 10 + 0.13x

x=120

Correct!

To determine the number of minutes for which the cost of the first and second plans will be equal, we can set up an equation and solve for the variable.

Let's represent the number of minutes as 'x'.

For the first plan, the total cost is calculated as follows:
Cost of calls = x minutes * $0.08/minute
Total cost of the first plan = $16 monthly fee + Cost of calls

For the second plan, the total cost is calculated as follows:
Cost of calls = x minutes * $0.13/minute
Total cost of the second plan = $10 monthly fee + Cost of calls

To find the point where the costs are equal, we can set up the equation:

$16 + (x * $0.08) = $10 + (x * $0.13)

Now, let's solve the equation for 'x'.

$16 + $0.08x = $10 + $0.13x

Subtract $0.08x and $10 from both sides of the equation:

$6 = $0.05x

Divide both sides by $0.05:

x = $6 / $0.05

x = 120

Therefore, the cost of the first and second plans will be equal for 120 minutes of calls.