6. Sarah counted her heartbeats after running. In 20 seconds, she counted 45 heartbeats. At that rate, what was her number of heartbeats per 1 min. (60 seconds)? 495

135

273

132

What are the constants in this expression? -10.6+9/10+2/5m-2.4n+3m

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) .

Triangle xyz has vertices x(1,3), y(0,0)