Help!! I’m confused and this is due soon

Which expression is equivalent to √ -80?

Frank has $66.50 in his account on sunday. over the next week, he makes the following changes to his balance via deposits and purchases: day debit ($) credit ($) monday 60.33 80.75 tuesday 54.45 wednesday 49.20 15.00 thursday 35.40 friday 16.85 75.00 saturday 80.56 on what day does frank first get charged an overdraft fee? a. wednesday b. thursday c. friday d. saturday select the best answer from the choices provided a b c d

The train station clock runs too fast and gains 5 minutes every 10 days. how many minutes and seconds will it have gained at the end of 9 days?