用递等式计算，能简算的要简算．
6÷
-
÷6． 1÷[
×（
-
）]．
×
+
÷
．
×9-8÷
． （21+
）×
+
．
×[2÷（
-
）]．
6÷
| 3 |
| 5 |
| 3 |
| 5 |
| 3 |
| 5 |
| 1 |
| 2 |
| 1 |
| 3 |
| 3 |
| 8 |
| 5 |
| 11 |
| 5 |
| 8 |
| 11 |
| 5 |
| 8 |
| 17 |
| 17 |
| 8 |
| 3 |
| 8 |
| 1 |
| 3 |
| 7 |
| 8 |
| 5 |
| 6 |
| 7 |
| 8 |
| 3 |
| 4 |
| 3 |
| 5 |
| 3 |
| 5 |
| 3 |
| 5 |
| 1 |
| 2 |
| 1 |
| 3 |
| 3 |
| 8 |
| 5 |
| 11 |
| 5 |
| 8 |
| 11 |
| 5 |
| 8 |
| 17 |
| 17 |
| 8 |
| 3 |
| 8 |
| 1 |
| 3 |
| 7 |
| 8 |
| 5 |
| 6 |
| 7 |
| 8 |
| 3 |
| 4 |
