`#laviken#`
`A` =`1+2+2^2+2^3+...+2^100`
`B` = `2^101`
$\Rightarrow$`2A`=`2+2^2+2^3+...+2^100+2^101`
$\Rightarrow$`2A-A`=`2+2^2+2^3+...+2^100+2^101` `-` `(1+2+2^2+2^3+...+2^100)`
$\Rightarrow$`2A-A`=`2+2^2+2^3+...+2^100+2^101` `-` `1-2-2^2-2^3-...-2^100`
$\Rightarrow$`A=``2^101-1`
Ta có : `2^101>2^101-1` Nên `B>A`
