Estimate the number of steps you would have to take to walk a distance equal to the circumference of the earth. (we estimate that the length of a step for an average person is about 18 inches, or roughly 0.5 m. the radius of the earth is 6.38 ✕ 106 m.)

Luke started a weight-loss program. the first week, he lost x pounds. the second week, he lost pounds less than times the pounds he lost the first week. the third week, he lost 1 pound more than of the pounds he lost the first week. liam started a weight-loss program when luke did. the first week, he lost 1 pound less than times the pounds luke lost the first week. the second week, he lost 4 pounds less than times the pounds luke lost the first week. the third week, he lost pound more than times the pounds luke lost the first week.