Evaluate the following expression when x = -1, y = 2, z = -3, and
w = 4.
x² - y²

Use the radius you found in part i (r=26.8 cm) with the surface area formula below to find the surface area of the sphere. show your work and round your answer to the nearest tenth. the surface area of a sphere: sa = 4πr^2 self note: 3.8.4

Answer asap ! the shortest path from point a to point b goes through a pond. to avoid the pond, you must walk straight 34 meters along one edge of the pond, then take a 90 degree turn, and again walk straight 41 meters along another edge of the pond to reach point b. about how many meters would be saved if it were possible to walk through the pond? a. 11 m b. 20 m c. 30.45 m d. 21.73 m

The weight of full–grown tomatoes at a farm is modeled by a normal distribution with a standard deviation of 18.4 grams. the 95 percent confidence interval for the mean weight of the tomatoes is calculated using a sample of 100 tomatoes. what is the margin of error (half the width of the confidence interval)?