Ratios equivalent to 10:9.

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).

Average acceleration: i have no idea how to do this.

X+ y = 5 ; x - y =3 solve using linear combination