Please help. This is a math assignment, I don’t know which number line to choose, please and thanks!

Arectangle has an area of 54 square feet. if the length is 3 feet more than the width, find the dimensions of the rectangle.

Simplify the expression. enter the correct answer.

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).