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For what numbers of minutes of local cost are the cost of the plans the same?

For what numbers of minutes of local cost are the cost of the plans the same?-example-1
User Rangooski
by
6.6k points

1 Answer

6 votes

ANSWER :

b. 75 minutes

EXPLANATION :

We can formulate a relation with the cost and minutes :


y=mx+b

where y = total cost

x = number of minutes

m = cost per minute of calls

and

b = fixed monthly fee

The first company charges b = $27.95 monthly fee and the rate is m = $0.12 per minute

The equation will be :


y=0.12x+27.95

The next company charges b = $12.95 a month and the rate is m = $0.32 per minute.

The equation will be :


y=0.32x+12.95

We are looking for the number of minutes (x) in which the total cost (y) are the same for both companies.

So we can equate y = y


\begin{gathered} y=y \\ 0.12x+27.95=0.32x+12.95 \end{gathered}

Solve for x :


\begin{gathered} 0.12x-0.32x=12.95-27.95 \\ -0.2x=-15 \\ x=(-15)/(-0.2) \\ \\ x=75 \end{gathered}

User Ernio
by
6.4k points
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