Trang chủ » Hỏi đáp » Môn Toán 1 + 2 + 2^2 + 2^3 + 2^4 + …. + 2^2000 25/03/2024 1 + 2 + 2^2 + 2^3 + 2^4 + …. + 2^2000
Đặt A=1+2+2^2+2^3+2^4+…+2^2000 2.A=2.(1+2+2^2+2^3+2^4+…+2^2000) 2A=2+2^2+2^3+2^4+2^5+…+2^2001 2A-A=(2+2^2+2^3+2^4+2^5+…+2^2001)-(1+2+2^2+2^3+2^4+…+2^2000) A=2^2001-1 Vậy A=2^2001-1 Trả lời
S = 1 + 2 + $2^{2}$ + $2^{3}$ + $2^{4}$ + … + $2^{2000}$ 2S = 2 + $2^{2}$ + $2^{3}$ + $2^{4}$ + … + $2^{2001}$ 2S – S = ( 2 + $2^{2}$ + $2^{3}$ + $2^{4}$ + … + $2^{2001}$ ) – ( 1 + 2 + $2^{2}$ + $2^{3}$ + $2^{4}$ + … + $2^{2000}$ ) S = $2^{2001}$ – 1 Trả lời
2 bình luận về “1 + 2 + 2^2 + 2^3 + 2^4 + …. + 2^2000”