Which expression represents the factorization of 57st - 21

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).

Terri makes a quilt using three sizes of fabric squares the side lenght of each fabric square is the square root of the area

Evaluate the expression for the given value of the variable. ∣-4b-8∣+∣-1-b^2 ∣+2b^3 ; b=-2