0.7+9.7+99.7+999.7+9999.7+99999.7+999999.7+9999999.7+99999999.7+999999999.7.
问题描述:
0.7+9.7+99.7+999.7+9999.7+99999.7+999999.7+9999999.7+99999999.7+999999999.7.
答
0.7+9.7+99.7+999.7+9999.7+99999.7+999999.7+9999999.7+99999999.7+999999999.7,
=(1-0.3)+(10-0.3)+(100-0.3)+(1000-0.3)+(10000-0.3)+(100000-0.3)+(1000000-0.3)+(1000000-0.3)+(100000000-0.3)+(1000000000-0.3),
=1111111111-0.3×10,
=1111111108.