This will probably do
Code:
SELECT trans1.Payee, -1*trans1.Amount AS TotalLoanAmount, Nz(trans2.Amount,0) AS TotalPaymentAmount, -1*(trans1.Amount + Nz(trans2.Amount,0)) AS RemainingLoanBalance
FROM
(SELECT t1.Payee, SUM(t1.TransAmount) AS Amount FROM tbl_Transactions t1 WHERE t1.TransAccountName = 4 AND t1.TransType = 1 GROUP BY t1.Payee) AS trans1
LEFT JOIN
(SELECT t2.Payee, SUM(t2.TransAmount) AS Amount FROM tbl_Transactions t2 WHERE t2.TransAccountName = 4 AND t2.TransType = 2 GROUP BY t2.Payee) AS trans2 ON trans2.Payee = trans1.Payee;