Equilateral, scalene, or isosceles?

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).

Three times the sum of a number and seven is negative thirty-six. what is the number?

At your job you're paid $50 per week plus $3 per sale at least how many saled do you need to make in order to have over $250