계산 2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18 + 20.

계산 2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18 + 20.


2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18 + 20, = (2 + 18) + (4 + 16) + (6 + 14) + (8 + 12) + 20 + 10, = 20 + 20 + 20 + 20 + 10, = 20 x 5 + 10, = 100 + 10, = 110.