下面各题，怎样算简便就怎样算（87-45）×7812×35+25×121320×19+13201011×113×13×11513×127+57×513-5132008×20062007（47+29）×7×95-3×79+291513-（79-813+29）-数学
=13；
（4）
| 10 |
| 11 |
| 1 |
| 13 |
=（
| 10 |
| 11 |
| 1 |
| 13 |
=10×1，
=10；
（5）
| 5 |
| 13 |
| 2 |
| 7 |
| 5 |
| 7 |
| 5 |
| 13 |
| 5 |
| 13 |
=
| 5 |
| 13 |
| 2 |
| 7 |
| 5 |
| 7 |
=
| 5 |
| 13 |
=
| 5 |
| 13 |
（6）2008×
| 2006 |
| 2007 |
=（2007+1）×
| 2006 |
| 2007 |
=2007×
| 2006 |
| 2007 |
| 2006 |
| 2007 |
=2006+
| 2006 |
| 2007 |
=2006
| 2006 |
| 2007 |
（7）（
| 4 |
| 7 |
| 2 |
| 9 |
=（
| 4 |
| 7 |
