A new club opens with 20 members, plus an unknown number of members x from another club. The club allows only members to join once a year. After the first year, the number of total members doubles. The following year, half of the members that joined from the other club leave, but another 40 people join. After the third year, the total number of members triples. Give a non-simplified expression that represents the total number of members at the club after the third year. [Help!]

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.