how use of and in .where ling code example

Example 1: linq c# where condition

var query = MemberTable.Where(x=>x.sex.Equals(Sex))

if (members != null)
     query = query.Where(x=>members.Contains(x.membercode))

//use your query
query.ToList();

Example 2: linq query select where c#

var queryLondonCustomers = from cust in customers
                           where cust.City == "London"
                           select cust;