Si
citabas ese mensaje te dabas cuenta de cómo hacerlo. Así:
[HIGHLIGHT="MySQL"]mysql> SELECT * FROM restar; SELECT * FROM saldo;
+----------+---------+------------+---------+
| nfactura | cedula | nombre | entrego |
+----------+---------+------------+---------+
| 133 | 3230148 | ARIEL DIAZ | 15000 |
| 133 | 3230148 | ARIEL DIAZ | 5000 |
| 133 | 3230148 | ARIEL DIAZ | 10000 |
| 133 | 3230148 | ARIEL DIAZ | 5000 |
| 134 | 3230148 | ARIEL DIAZ | 1000 |
| 134 | 3230148 | ARIEL DIAZ | 1000 |
+----------+---------+------------+---------+
+----------+---------+------------+-------+
| nfactura | cedula | nombre | total |
+----------+---------+------------+-------+
| 133 | 3230148 | ARIEL DIAZ | 40000 |
| 134 | 3230148 | ARIEL DIAZ | 6000 |
+----------+---------+------------+-------+[/HIGHLIGHT]