According to Descartes rule what is the possible number of positive roots and negative roots

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

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Three numbers x, y, and z are in the ratio 2: 7: 8. if 12 is subtracted from y, then three numbers form a geometric sequence (in the order x, y–12, z). find x, y, and z. there are 2 sets.