Trying to find the difference between two sub-totals (sales - credits)

Hi, Please take a look and tweak accordingly. You may pay attention to nulls and manipulate accordingly. Best of luck!

--Option 1
SELECT  t2.ItemCode,( SUM(T2.TotalSales)-SUM(TotalCredits))  AS 'Total'
FROM
(
        SELECT T0.ItemCode, SUM(T0.LineTotal) as 'TotalSales',SUM(0) as 'TotalCredits'
        FROM INV1 as T0
        WHERE T0.ItemCode = 'ACR2401010'
        GROUP BY T0.ItemCode

        UNION ALL

        SELECT T1.ItemCode, SUM(0) as 'TotalSales', SUM(T1.LineTotal) as 'TotalCredits', 
        FROM RIN1 as T1
        WHERE T1.ItemCode = 'ACR2401010'
        GROUP BY T1.ItemCode

) AS t2
GROUP BY t2.ItemCode

--Option 2
SELECT  t2.ItemCode, ( SUM(T2.TotalSales)-SUM(TotalCredits)) AS 'Total'
FROM
(
        SELECT T0.ItemCode, SUM(T0.LineTotal) as 'TotalSales',SUM(0) as 'TotalCredits'
        FROM INV1 as T0
        --WHERE T0.ItemCode = 'ACR2401010'
        GROUP BY T0.ItemCode

        UNION ALL

        SELECT T1.ItemCode, SUM(0) as 'TotalSales', SUM(T1.LineTotal) as 'TotalCredits', 
        FROM RIN1 as T1
        --WHERE T1.ItemCode = 'ACR2401010'
        GROUP BY T1.ItemCode

) AS t2
WHERE t2.ItemCode = 'ACR2401010'
GROUP BY t2.ItemCode

--Option 3
SELECT  t2.ItemCode, ( SUM(T2.TotalSales)-SUM(TotalCredits) ) AS 'Total'
FROM
(
        SELECT T0.ItemCode, T0.LineTotal as 'TotalSales', 0 as 'TotalCredits'
        FROM INV1 as T0
        
        UNION ALL
        
        SELECT T1.ItemCode, 0 as 'TotalSales', T1.LineTotal as 'TotalCredits', 
        FROM RIN1 as T1


) AS t2
WHERE t2.ItemCode = 'ACR2401010'
GROUP BY t2.ItemCode

--Assuming credit part is optional..also assuming each table should return only one row else results would inflate...option 4
SELECT  t0.ItemCode, ( SUM(T0.TotalSales)-SUM(T1.TotalSales)) AS 'Total'
FROM
INV1 as t0
left outer join
RIN1 as t1
ON t0.ItemCode = t1.ItemCode
WHERE t0.ItemCode = 'ACR2401010'
GROUP BY t0.ItemCode

--option 4 with grouping to ensure single row from each table
SELECT  t0.ItemCode, ( isnull(T0.TotalSales,0)-isnull(T1.TotalSales,0)) AS 'Total'
FROM
(
        SELECT T0.ItemCode, SUM(T0.LineTotal) as 'TotalSales'
        FROM INV1 as T0
        --WHERE T0.ItemCode = 'ACR2401010'
        GROUP BY T0.ItemCode

)as t0
LEFT OUTER JOIN
(       SELECT T1.ItemCode,  SUM(T1.LineTotal) as 'TotalCredits', 
        FROM RIN1 as T1
        --WHERE T1.ItemCode = 'ACR2401010'
        GROUP BY T1.ItemCode 
) as t1
ON t0.ItemCode = t1.ItemCode
WHERE t0.ItemCode = 'ACR2401010'


--Option 5 with grouping to ensure single row from each table. 
--Also assuming that sales or credits can be optional 
SELECT 
 ISNULL(t0.ItemCode,t0.ItemCode) AS ItemCode,  
( isnull(T0.TotalSales,0)-isnull(T1.TotalSales,0)) AS 'Total'
FROM
(
        SELECT T0.ItemCode, SUM(T0.LineTotal) as 'TotalSales'
        FROM INV1 as T0
        --WHERE T0.ItemCode = 'ACR2401010'
        GROUP BY T0.ItemCode

)as t0
FULL OUTER JOIN
(       SELECT T1.ItemCode,  SUM(T1.LineTotal) as 'TotalCredits', 
        FROM RIN1 as T1
        --WHERE T1.ItemCode = 'ACR2401010'
        GROUP BY T1.ItemCode 
) as t1
ON t0.ItemCode = t1.ItemCode
WHERE (t0.ItemCode = 'ACR2401010' OR t1.ItemCode = 'ACR2401010')