10/27 < 10/15, 9/16 < 9/15, 11/34 < 11/15
=>10/27 + 9/16 + 11/34 < 10/15 + 9/15 + 11/15
=>A < 30/15
=>A < 2 (đpcm)
10/27 < 10/15, 9/16 < 9/15, 11/34 < 11/15
=>10/27 + 9/16 + 11/34 < 10/15 + 9/15 + 11/15
=>A < 30/15
=>A < 2 (đpcm)
Chuwngs minh A=\(\frac{1}{3}\)+\(\frac{2}{9}\)+\(\frac{3}{27}\)+...+\(\frac{100}{3^{100}}\)>\(\frac{3}{4}\)
Tính \(A=16-\frac{\frac{-2}{9}+\frac{-2}{10}+\frac{-2}{11}+...+\frac{-2}{2020}}{\frac{1}{27}+\frac{1}{30}+\frac{1}{33}+...+\frac{1}{6060}}\)
Rut gon: \(A=\frac{9+\frac{9}{11}+\frac{18}{23}-\frac{27}{27}}{8+\frac{8}{11}+\frac{16}{23}-\frac{24}{37}}-\frac{2+\frac{16}{29}-\frac{24}{13}-\frac{32}{11}}{3+\frac{24}{29}-\frac{36}{13}-\frac{48}{11}}\)
\(a=\frac{\frac{5}{3}+\frac{5}{9}-\frac{5}{27}}{8-\frac{8}{3}+\frac{8}{9}-\frac{8}{27}}:\frac{15-\frac{15}{11}+\frac{15}{121}}{16-\frac{16}{11}+\frac{16}{121}}\)
ngày 27/2 mình sẽ giai ai giải đung sẽ dc 20 dung
A=\(\frac{\left(9\frac{3}{4}:5,2+3,4.2\frac{7}{34}\right):1\frac{9}{16}}{0,31.8\frac{2}{5}-5,61:27\frac{1}{2}}\).Rút gọn A
Tính giá trị biểu thức A biết:
\(A=16-\frac{-\frac{2}{9}-\frac{2}{10}-\frac{2}{11}-...-\frac{2}{2020}}{\frac{1}{27}+\frac{1}{30}+\frac{1}{33}+...+\frac{1}{6060}}\)
Chứng tỏ :
S = \(\frac{1}{201}\)+ \(\frac{1}{202}\)+.........+\(\frac{1}{399}\)+\(\frac{1}{400}\)>\(\frac{1}{2}\)
A = \(\frac{10}{27}\)+ \(\frac{9}{16}\)+ \(\frac{11}{34}\)< 2
Tính:
a) \(\frac{\frac{3}{5}+\frac{3}{27}-\frac{3}{9}-\frac{3}{11}}{\frac{4}{5}+\frac{4}{27}-\frac{4}{9}-\frac{4}{11}}\)
b) \(\frac{5-\frac{5}{3}-\frac{5}{27}}{8-\frac{8}{3}-\frac{8}{27}}:\frac{15+\frac{15}{121}-\frac{15}{11}}{16+\frac{16}{121}-\frac{16}{11}}\)
c) \(\frac{1}{2}:\left(\frac{-3}{2}\right):\frac{4}{3}:\left(\frac{-5}{4}\right):\frac{6}{5}:\left(\frac{-7}{6}\right):...:\left(\frac{-101}{100}\right)\)
Mọi người nhớ đánh nhanh câu trả lời giúp mình nhé!!
\(\frac{5-\frac{5}{3}+\frac{5}{9}-\frac{5}{27}}{8-\frac{8}{3}+\frac{8}{9}-\frac{8}{27}}:\frac{15-\frac{15}{11}+\frac{15}{121}}{16-\frac{16}{11}+\frac{16}{121}}\)