Question 1047624
For what integer n is {{{(10^n-1)*(10^n+1) = 999999999999}}}?
---
{{{(10^n-1)*(10^n+1) = 10^12 - 1 }}}
{{{10^(2n) - 1 = 10^12 - 1 }}}
2n = 12
n = 6