For her phone service , Rania pays a monthly fee of $ 18 , and an additional $0.06 per minute of use. The least she has been charged in a month is $88.56

I'm assuming we need to find the number of minute she as used. to do that we can right an inequality with m being the number of minutes

18+0.06m≥88.56

we then just solve this like we would with any other algebra equation, First we subtract 18 from both sides.

0.06m≥70.56

Then we dives by 0.06

m≥1176

Rania has used at least 1176 minutes