0.02+0+04+0+06+…+19.96+19.98 简便计算
问题描述:
0.02+0+04+0+06+…+19.96+19.98 简便计算
错了,是0.02+0.04+0.06+…+19.96+19.98
答
0.02+0.04+0.06+…+19.96+19.98
=(0.02+19.98)×999/2
=20×999/2
=10×999
=9990