total valor factura

SELECT SUM(QUANTxPRECO) AS TOTALSOMADO, idFatura FROM (
SELECT (V.QUANTIDADE * A.PRECO) AS QUANTxPRECO,V.idFatura
FROM VendasArtigos AS V
JOIN Artigo AS A ON
V.idArtigo = A.idArtigo
JOIN Fatura AS F
ON V.idFatura = F.idFatura
) AS X
GROUP BY idFatura