The reciprocal of 3, plus the reciprocal of 7, is the reciprocal of what number?​

Which of the following transformations does not preserve congruence? * 5 points a. (x, y) → (y − 3, x − 3) b. (x, y) → (x + 5, y − 1) c. (x, y) → (y + 9, −x + 2) d. (x, y) → (3x + 1, 3y − 2)

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).

Abus travels 36 miles in 45 minutes. enter the number of miles the bus travels in 60 minutes at this rate.