(6分) 如图①、图②、图③……是用围棋子摆成的一列具有一定规律的“山”字．
(1) 按图示的规律填空．
| 图形标号 | ① | ② | ③ | ④ | …… |
| 围棋子的数目(颗) | 7 |
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(2) 第n个图形所对应的围棋子的数目为___________颗．
若某个图形中有围棋子142颗，它是第__________个图形．
(6分) 如图①、图②、图③……是用围棋子摆成的一列具有一定规律的“山”字．
(1) 按图示的规律填空．
| 图形标号 | ① | ② | ③ | ④ | …… |
| 围棋子的数目(颗) | 7 |
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(2) 第n个图形所对应的围棋子的数目为___________颗．
若某个图形中有围棋子142颗，它是第__________个图形．
(1) 12，17，22
(2) 
(3) 28
解析:
解：(1) 12，17，22···················································································· 3分
(2) ·················································································· 5分
(3) 28·························································································· 6分