For his long distance phone service, lamar pays a $3 monthly fee plus 11 cents per minute. last month, lamar's long distance bill was $20.82 . for how many minutes was lamar billed

Let the number of minutes be = x.

Cost per minute = 11 cents = 0.11

Phone Bill = Monthly fee  +    0.11* x 

Substituting from the question

20.82 = 3 + 0.11x

3 + 0.11x = 20.82

0.11x = 20.82 - 3

0.11x = 17.82

x = 17.82/0.11

x = 162  

Lamar was billed for 162 minutes.