0.9+0.99+0.999+0.9(10个9)9
=(1-0.1)+(1-0.01)+(1-0.001)+…+(1-0.000000001)
10个0
=1-0.1+1-0.01+1-0.001+…+1-0.0000000001
=(1+1+…+1)-0.1-0.01-…-0.0000000001
10个1
=10-0.11…1
10个1
=9.8…89
9个8
0.9+0.99+0.999+0.9(10个9)9
=(1-0.1)+(1-0.01)+(1-0.001)+…+(1-0.000000001)
10个0
=1-0.1+1-0.01+1-0.001+…+1-0.0000000001
=(1+1+…+1)-0.1-0.01-…-0.0000000001
10个1
=10-0.11…1
10个1
=9.8…89
9个8