x y First Second Third Fourth
Difference Difference Difference Difference
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1 1
4 - 1 = 3
2 4 5 - 3 = 2
9 - 4 = 5 2 - 2 = 0
3 9 7 - 5 = 2 0 - 0 = 0
16 - 9 = 7 2 2 = 0
4 16 9 - 7 = 2
25 - 16 = 9
5 25