12.观察下表,填表后再解答问题:
(1)试完成下列表格:
(2)第n个图形中有多少个“●”和多少个“★”?
(3)试求第几个图形中有120个“●”?并求该图形中有多少个“★”.
0 297532 297540 297546 297550 297556 297558 297562 297568 297570 297576 297582 297586 297588 297592 297598 297600 297606 297610 297612 297616 297618 297622 297624 297626 297627 297628 297630 297631 297632 297634 297636 297640 297642 297646 297648 297652 297658 297660 297666 297670 297672 297676 297682 297688 297690 297696 297700 297702 297708 297712 297718 297726 366461
(1)试完成下列表格:
| 序号 | 1 | 2 | 3 | … |
| 图形 | … | |||
| ●的个数 | 8 | 16 | 24 | … |
| ★的个数 | 1 | 4 | 9 | … |
(3)试求第几个图形中有120个“●”?并求该图形中有多少个“★”.