Rewrite the expression using positive exponents 1. 1/9x^-2y^-1

2. a^-5xa^-8
CHOSE FOR #2 :
A) 1/a^14
B) a^14
C)a^14
D)1/a^48

PLZ HELP

The random variable x is the number of occurrences of an event over an interval of ten minutes. it can be assumed that the probability of an occurrence is the same in any two-time periods of an equal length. it is known that the mean number of occurrences in ten minutes is 5.3. the appropriate probability distribution for the random variable