Question

tính:S=2^100-2^99+2^98+...+2^2-2

Answer 1

S=2¹⁰⁰-2⁹⁹+2⁹⁸+...+2²-2

=>2S=2¹⁰¹-2¹⁰⁰+2⁹⁹-....+2³-2²

=>2S+S=2¹⁰¹-2

=>3S=2¹⁰¹-2

=> S=(2¹⁰¹-2):3