------
## 最终结论
```python
def freq_element(list_of_lists):
    from collections import Counter
    flat_list = [item for sublist in list_of_lists for item in sublist]
    frequency = Counter(flat_list)
    return dict(frequency)

# Test cases
assert freq_element([[1, 2, 3, 2], [4, 5, 6, 2], [7, 1, 9, 5]]) == {2: 3, 1: 2, 5: 2, 3: 1, 4: 1, 6: 1, 7: 1, 9: 1}
assert freq_element([[1,2,3,4],[5,6,7,8],[9,10,11,12]]) == {1: 1, 2: 1, 3: 1, 4: 1, 5: 1, 6: 1, 7: 1, 8: 1, 9: 1,
                                                            10: 1,11: 1 ,12:1}
assert freq_element([[15,20,30,40],[80,90,100,110],[30,30,80,90]]) == {30:3 ,80 :2 ,90 :2 ,15 :1 ,20 :1 ,40 :1 ,
                                                                     100 :1 ,110 :1 }
```