Really need help with this word problem

Question

The phone company charges you a different rate for the first minute of a call then each additional minute. You see on your bill that a 12 minute call costs $2.03 and an 18 minute call costs $2.81. What are the costs of the first minute and each additional minute?

Rrequires 2 variables and 2 equations.

Answer 1

Renne, you’ll probably know how to do this problem once the words have been translated to math.

First, give a name (a”variable”) to each quantity.

Let F be the cost of the first minute.

Let S be the cost of the second minute and each minute after.

Now translate the other words using these variable names.

Translate “a 12-minute call costs $2.03” into

F + 11*S = 2.03

Notice the 12 minute call has 11 minutes that aren’t the first. So the total cost is one First minute and 11 Subsequent minutes, which we are told is 2.03

TrAnslate the other statement similarly:

F + 17*S = 2.81

So your two equations in two unknowns are:

F + 11*S = 2.03

F + 17*S = 2.81

Probably you already know how to solve these. As an example, try eliminating F.

Subtract the first equation from the second.

0 + 6*S = 0.78

Divide by 6

S = 0.13

Now that you’ve found S, put its value back into one of the equations and solve for F.

F + 11*S = 2.03

F + 11* 0.13 = 2.03

F + 1.43 = 2.03

I’m sure you can finish finding the value of F from here.