C# writing an linq statement form an SQL with a join

SELECT e.memberid, e.spid, e.Score, m.Class
FROM   Mem AS e INNER JOIN
       Members AS m ON e.memberid = m.membersid
WHERE  (e.Score =
           (SELECT MAX(Score) AS Expr1
            FROM   Mem AS w
            WHERE  (memberid = e.memberid))
       ) 
AND 
       (m.Class = '1st grade')

var maxScore2 = (from z in storeDB.Mem join mg in storeDB.Members on z.memberid equals mg.memberid)
    .Where(e => e.Score == storeDB.Mem.Where(w => w.memberid == e.memberid).Max(w => w.Score))
    .Where(t => t.sid == (i + 1))
    .Select(e => new { e.memberid, e.spid, e.Score });

var mem_con_mem = from h in m_members
                  join mg in storeDB.Mem on h.memberid equals mg.memberid 
                  select h.First_Name;
                                    
maxScore2 = mem_con_mem
    .Where(e => e.Score == storeDB.Mem.Where(w => w.memberid == e.memberid).Max(w => w.Score))
    .Where(t => t.spid == (i + 1))
    .Select(e => new { e.memberid, e.spid, e.Score });