Question

When making a long distance call from a certain pay phone, the first three minutes of a call cost $3.00. afterthat, each additional minute or portion of a minute of that call costs $0.45. use an inequality to find the numberof minutes one can call long distance for $8.40?

Answer 1

3 + 0.45*M<=8,40. Notice the equal, because you may use all the money. Then, rearranging: M<=(8.40-3)/0.45= 12, so M<=12. Now, obviously time is positive, so you may end saying 0<=M<=12, with M=0 meaning no call! :)