808和809这两个数字哪个更好？

806 + 807 + 808 + 809 + 810 + 811 + 812 = (809 - 3) + (809 -2) + (809 - 1) + 809 + (809 + 1) + (809 + 2) + (809 + 3) = 809×5 + (-3 - 2 - 1 + 0 + 1 + 2 + 3) = 4045 + 0 = 4045

匿名回答于2024-06-01 09:18:49