With a headwind a plane traveled 128 km in 2h. The return trip with a tail wind took 24 min less. Find the air speed of the plane. A. 64 km/h B. 72km/h C. 80km/h D. 88km/h E. 96km/h

In order for the function to be linear, what must m be and why? m = 22 because the rate of change is 1. m = 20 because the rate of change is 3. m = 22 because the rate of change is -1. m = 20 because the rate of change is -3.