Đáp án + Giải thích các bước giải:
`N=1/2^0+1/2^2+1/2^4+...+1/2^100`
`=>N=1+1/2^2+1/2^4+...+1/2^100`
`=>2N=2+1/2+1/2^3+...+1/2^99`
`=>2N+N=2+1/2+1/2^3+...+1/2^99+1+1/2^2+1/2^4+...+1/2^100`
`=>3N=3+1/2+1/2^2+1/2^3+1/2^4+...+1/2^99+1/2^100`
`=>6N=6+1+1/2+1/2^2+1/2^3+...+1/2^98+1/2^99`
`=>6N=7+1/2+1/2^2+1/2^3+...+1/2^98+1/2^99`
`=>6N-3N=(7+1/2+1/2^2+1/2^3+...+1/2^98+1/2^99)-(3+1/2+1/2^2+1/2^3+1/2^4+...+1/2^99+1/2^100)`
`=>3N=4-1/2^100`
`=>3N=(2^102-1)/(2^100)`
`=>N=(2^102-1)/(2^100):3`
`=>N=(2^102-1)/(2^100). 1/3`
`=>N=(2^102-1)/(3.2^100)`
