Somebody helpp?

An airport in death valley is 60 feet below sea level, and an airplane is flying 2,000 feet above sea level. how many feet must the plane descend in order to land? a. 2060 b. 2000 feet c. 1940 feet d. 1880 feet e.1400 feet will mark as brainliest

Identify the type of observational study described. a statistical analyst obtains data about ankle injuries by examining a hospital's records from the past 3 years. cross-sectional retrospective prospective

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 - 4x - 5 = 0