Vì mấy cái kia cộng lại sẽ bằng 0,477..
1/2=0,5 nên tổng kia sẽ nhỏ hơn 1/2
Đúng 0
Bình luận (0)
Các câu hỏi tương tự
CMR :
a) \(\frac{1}{3}+\frac{1}{31}+\frac{1}{35}+\frac{1}{37}+\frac{1}{47}+\frac{1}{53}+\frac{1}{61}< \frac{1}{2}\)
b) \(\frac{1}{6}< \frac{1}{5^2}+\frac{1}{6^2}+....+\frac{1}{100^2}< \frac{1}{4}\)
a,\(\frac{1}{2}-\left(\frac{-2}{5}\right)+\frac{1}{3}+\frac{5}{7}-\left(\frac{-1}{6}\right)+\frac{-4}{35}+\frac{1}{41}\)
b,\(0,75.\frac{3}{37}-\frac{3}{4}.\frac{29}{37}-\frac{15}{20}.\frac{11}{37}-0.25\)
CMR :
\(\left(1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{99}\right)-\left(\frac{1}{2}+\frac{1}{4}+\frac{1}{6}+...+\frac{1}{100}\right)\)
\(=\frac{1}{51}+\frac{1}{52}+\frac{1}{53}+\frac{1}{100}\)
\(cmr;\frac{1}{1\times2}+\frac{1}{3\times4}+\frac{1}{5\times6}+.....+\frac{1}{99\times100}=\frac{1}{51}+\frac{1}{52}+\frac{1}{53}+.....+\frac{1}{100}\)
ai làm đung mình tick cho
1)\(|x-\frac{2}{7}|=\frac{-1}{5}.\frac{-5}{7}\)
2)\(\left(\frac{1}{2}-1\right)\left(\frac{1}{3}-1\right).....\left(\frac{1}{2008}-1\right)\left(\frac{1}{2009}-1\right)\)
3) Chứng tỏ rằng \(5^{61}+25^{31}+125^{21}\)chia hết cho 31
4)Tìm giá trị nhỏ nhất của biểu thức: \(A=|x-2011|+|x-200|\)
a, frac{4}{9.13}+frac{11}{13.24}+frac{7}{38.45}b, left(frac{-3}{8}+frac{5}{9}:frac{-11}{37}right).left(frac{33}{19}-frac{7}{22}.frac{47}{17}right).left(2-frac{7}{13}.frac{7}{26}right)c, 3.left|2-1frac{1}{14}right|-left|3left(frac{-3}{7}right)right|-2left(4,025-2,885right)d,left(frac{1}{4}-1right)left(frac{1}{5}-1right).....left(frac{1}{2000}-1right)left(frac{1}{2001}-1right)
Đọc tiếp
a, \(\frac{4}{9.13}+\frac{11}{13.24}+\frac{7}{38.45}\)
b, \(\left(\frac{-3}{8}+\frac{5}{9}:\frac{-11}{37}\right).\left(\frac{33}{19}-\frac{7}{22}.\frac{47}{17}\right).\left(2-\frac{7}{13}.\frac{7}{26}\right)\)
c, \(3.\left|2-1\frac{1}{14}\right|-\left|3\left(\frac{-3}{7}\right)\right|-2\left(4,025-2,885\right)\)
d,\(\left(\frac{1}{4}-1\right)\left(\frac{1}{5}-1\right).....\left(\frac{1}{2000}-1\right)\left(\frac{1}{2001}-1\right)\)
Tính nhanh :
\(C=\frac{1}{3}+\frac{-3}{4}+\frac{3}{5}+\frac{1}{57}+\frac{-1}{36}+\frac{1}{15}+\frac{-2}{9}\)
\(D=\frac{1}{2}+\frac{-1}{5}+\frac{-5}{7}+\frac{1}{6}+\frac{-3}{35}+\frac{1}{3}+\frac{1}{41}\)
\(E=\frac{-1}{2}+\frac{3}{5}+\frac{-1}{9}+\frac{1}{127}+\frac{-7}{18}+\frac{4}{35}+\frac{2}{7}\)
Bài 4 : Tính bằng cách hợp lí nếu có thểA0.5+frac{1}{3}+0.4+frac{5}{7}+frac{1}{6}-frac{4}{35}B-66(frac{1}{2}-frac{1}{3}+frac{1}{11})+124*(-37)+63*(-124)Cfrac{8}{9}+frac{1}{2}-frac{1}{6}-frac{1}{12}-frac{1}{20}-frac{1}{30}-frac{1}{42}-frac{1}{56}-frac{1}{72}Dfrac{1}{1cdot3}-frac{1}{2cdot4}+frac{1}{3cdot5}-frac{1}{4cdot6}+....+frac{1}{97cdot99}-frac{1}{98cdot100}Efrac{frac{1}{3}-frac{1}{7}-frac{1}{13}}{frac{2}{3}-frac{2}{7}-frac{2}{13}}*frac{frac{1}{3}-0.25+0.2}{1frac{1}{6}-0.875+0.7}+frac{6}{7}
Đọc tiếp
Bài 4 : Tính bằng cách hợp lí nếu có thể
A=0.5+\(\frac{1}{3}\)+0.4+\(\frac{5}{7}\)+\(\frac{1}{6}\)-\(\frac{4}{35}\)
B=-66(\(\frac{1}{2}\)-\(\frac{1}{3}+\frac{1}{11}\))+124*(-37)+63*(-124)
C=\(\frac{8}{9}+\frac{1}{2}-\frac{1}{6}-\frac{1}{12}-\frac{1}{20}-\frac{1}{30}-\frac{1}{42}-\frac{1}{56}-\frac{1}{72}\)
D=\(\frac{1}{1\cdot3}-\frac{1}{2\cdot4}+\frac{1}{3\cdot5}-\frac{1}{4\cdot6}+....+\frac{1}{97\cdot99}-\frac{1}{98\cdot100}\)
E=\(\frac{\frac{1}{3}-\frac{1}{7}-\frac{1}{13}}{\frac{2}{3}-\frac{2}{7}-\frac{2}{13}}\)*\(\frac{\frac{1}{3}-0.25+0.2}{1\frac{1}{6}-0.875+0.7}+\frac{6}{7}\)
\(a,\frac{-5}{14}-\frac{37}{14}\le x