can anyone help i graduate in 7 days and if i don't get this stuff done i will not graduate please help will give brainiest and 20 points so please help

Rewrite the following without an exponent. (5/8)-1

The parabola x= √y-9 opens: a.)up b.)down c.)right d.)left

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?