For a long-distance person-to-person telephone call, a telephone company charges $ 0.21 for the first minute, $ 0.17 for each additional minute, and a $ 1.59 service charge. If the cost of a call is $ 2.31 comma how long did the person talk?

4 minutes

Step-by-step explanation:

total cost is $2.31

subtract $ 2.31-1.59 = 0.72 (base fee)

then $0.72-0.21=$0.51 (first minute fee)

lastly $0.51/0.17=3 (amount for each additional fee)

so then just add the first additional minutes with the amount from the additional minutes (3) to get a total of 4 minutes

4 minutes

Step-by-step explanation:

0.21+1.59=1.8

2.31=0.17x+1.8

Subtract 1.8 from both sides

0.51=0.17x

Divide both sides by 0.17

3=x

3 minutes plus the original minute spent talking

They spent 4 minutes total talking on the phone