Can someone please help me with this I would really appreciate it !!

Determine the mean and variance of the random variable with the following probability mass function. f(x)=( 729divided by 91) (1 divided by 9) superscript x baseline comma x equals 1,2,3 round your answers to three decimal places (e.g. 98.765).

Which of the following answers is 5/25 simplified? 1/5 5/5 2/5 1/25

If f(x)= sqrt4x+9+2, which inequality can be used to find the domain of f(x)?