Twenty planes are at an airport. Eight planes take off, then five planes land, then 7 more take off, then 9 land. How many planes are left at the airport? PLS HELPP

Mary beth used the mapping rule to find the coordinates of a point that had been rotated 90° counterclockwise around the origin. examine the steps to determine whether she made an error. m (3, –6) is rotated 90° counterclockwise. (x, y) → (–y, x) 1. switch the x- and y-coordinates: (6, –3) 2. multiply the new x-coordinate by –1: (6(–1), –3) 3. simplify: (–6, –3) .

Lines b and c are parallel. what is the measure of 2? m2 = 31° m2 = 50° m2 = 120° m2 = 130°

If the diagram polygon abcd is a reflection across ef to make polygon a'b'c'd'.