Which of the following show the Associative Property of Addition? 3 • (6 • 10) = (3 • 6) • 10
3(6 + 10) = 3 • 6 + 3 • 10
3 + (6 + 10) = (3 + 6) + 10
3 – (6 + 10) = (3 – 6) + 10

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 ordered pair is a solution to the system of linear equations? 2x + 3y= 6 –3x + 5y = 10

Kayla wants to find the width, ab, of a river. she walks along the edge of the river 65 ft and marks point c. then she walks 25 ft further and marks point d. she turns 90° and walks until her location, point a, and point c are collinear. she marks point e at this location, as shown. (a) can kayla conclude that δ and δ are similar? why or why not? (b) suppose de = 15 ft. what can kayla conclude about the width of the river?