Plz i don't want understand this who is smart enough? ?

Rose bought a new hat when she was on vacation. the following formula describes the percent sales tax rose paid b=t-c/c

Which choice names the hypotenuse of triangle xyz? a. segment yx b. segment yz c. segment ab d. segment zx

After reading 80% of her e-mails in her inbox, danette still has m unread e-mails. which of the following expressions could represent the number of e-mails danette had in her inbox before she started reading? choose 2 answers: (choice a) 5m (choice b) 1.8m (choice c) 80m (choice d) m/0.8 (choice e) m/1−0.8