99...9*88...8/66...6
=(9*11...1)*(8*11...1)/(6*11...1)
=11...1*9*8/6
=11...1*12
=11...1*(10+2)
=11...10+22...2
=13...32
以上各“...”代表1999个与前后位相同的数字
99...9*88...8/66...6
=(9*11...1)*(8*11...1)/(6*11...1)
=11...1*9*8/6
=11...1*12
=11...1*(10+2)
=11...10+22...2
=13...32
以上各“...”代表1999个与前后位相同的数字