Cho: \(A=\dfrac{3}{2}-\dfrac{7}{4}+\dfrac{11}{8}-\dfrac{15}{16}+...+\dfrac{99}{2^{25}}\)
CMR: A < \(\dfrac{9}{5}\)
bài 1: tính
a) \(\dfrac{5^4.20^4}{25^5.4^5}\) b)3,5-\(\left(-\dfrac{2}{7}\right)\) c)\(\left(\dfrac{11}{12}:\dfrac{33}{16}\right).\dfrac{3}{5}\) d)\(15.\left(-\dfrac{2}{3}\right)^2.-\dfrac{7}{3}\) e)\(\left(\dfrac{9}{25}-2.8\right):\left(3\dfrac{4}{5}+0,2\right)\) g)\(\dfrac{21}{47}+\dfrac{9}{45}+\dfrac{26}{47}+\dfrac{4}{5}\) h)\(\dfrac{15}{12}+\dfrac{5}{13}-\dfrac{3}{12}-\dfrac{18}{13}\) j)12.\(\left(-\dfrac{2}{3}\right)^2+\dfrac{4}{3}\) k)\(\dfrac{13}{25}+\dfrac{6}{41}-\dfrac{38}{25}+\dfrac{35}{41}-\dfrac{1}{2}\) l)12,5.\(\left(-\dfrac{5}{7}\right)+1,5.\left(-\dfrac{5}{7}\right)\) m)\(\sqrt{\dfrac{64}{25}}.3\dfrac{1}{2}-\dfrac{3}{5}.3\dfrac{1}{2}\)
1. thực hiện phép tính
a. 0,25: ( 10,3-9,8)-\(\dfrac{3}{4}\)
b. \(\dfrac{-5}{9}\).\(\dfrac{13}{28}\)-\(\dfrac{13}{28}\).\(\dfrac{4}{9}\)
c. \(\dfrac{6}{7}\)+\(\dfrac{5}{8}\):5-\(\dfrac{3}{16}\)
d. \(\dfrac{-5}{7}\).\(\dfrac{2}{11}\)+\(\dfrac{-5}{7}\).\(\dfrac{9}{11}\)+\(1\dfrac{5}{7}\)
e.\(\dfrac{-7}{12}\)-\(\dfrac{8}{15}\)+\(\dfrac{11}{20}\)
f. \(\dfrac{-17}{25}\).\(\dfrac{20}{33}\)+\(\dfrac{-17}{25}\).\(\dfrac{13}{33}\)+\(\dfrac{-3}{25}\)
câu 1 . Thực hiện phép tính
a. 0,05 + 5 - \(\dfrac{1}{2}\)
b. \(\dfrac{6}{15}-\dfrac{7}{8}+3-\dfrac{3}{5}-\dfrac{2}{16}\)
c. \(\dfrac{3}{5}.\dfrac{15}{7}-\dfrac{15}{7}.\dfrac{8}{5}\)
d. \(\dfrac{2}{5.7}+\dfrac{2}{7.9}+\dfrac{2}{9.11}+....+\dfrac{2}{93.99}\)
e. \(\dfrac{7}{4}:\dfrac{-9}{8}-\dfrac{3}{9}\)
f. \(\dfrac{15}{17}.\dfrac{19}{21}+\dfrac{19}{21}.\dfrac{2}{17}+\dfrac{13}{21}\)
g. \(\left(4-\dfrac{5}{12}\right):2+\dfrac{5}{24}\)
Tính
\(A=-\dfrac{11}{12}\cdot-\dfrac{4}{33}\cdot\dfrac{84}{-25}\cdot\dfrac{5}{8}\)
\(B=3\dfrac{2}{7}\cdot12\dfrac{2}{7}-3\dfrac{2}{7}\cdot5\dfrac{1}{2}\)
Thực hiện phép tính sau:
a, |-0,75| + \(\dfrac{1}{4}-2\dfrac{1}{2}\)
b, \(15.\dfrac{1}{5}:\left(\dfrac{-5}{7}\right)-2\dfrac{1}{5}.\left(\dfrac{-7}{5}\right)\)
c, \(\dfrac{5}{17}+\dfrac{2}{3}-\dfrac{20}{12}+\dfrac{7}{9}+\dfrac{12}{17}\)
d, \(\dfrac{5}{15}+\dfrac{14}{25}-\dfrac{12}{9}+\dfrac{2}{7}+\dfrac{11}{25}\)
giúp mk nha mk đang cần gấp
\(A=\dfrac{\dfrac{3}{11}+1-\dfrac{3}{7}}{3+\dfrac{9}{11}-\dfrac{9}{7}}-\dfrac{\dfrac{1}{3}+0,25-\dfrac{1}{5}+0.125}{\dfrac{7}{6}+\dfrac{7}{8}-0,7+\dfrac{7}{16}}\)
\(\dfrac{\left(13\dfrac{1}{4}-2\dfrac{5}{27}-10\dfrac{5}{6}\right).230\dfrac{1}{25}+46\dfrac{3}{4}}{\left(1\dfrac{3}{10}+\dfrac{10}{3}\right):\left(12\dfrac{1}{3}-14\dfrac{2}{7}\right)}\)
\(\dfrac{\left(1+2+3+...+99+100\right)\left(\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{1}{7}-\dfrac{1}{9}\right)\left(63.1,2-21.3,6\right)}{1-2+3-4+.....+99-100}\)
4. thực hiện phép tính
a.\(\dfrac{4}{9}+\dfrac{11}{125}-\dfrac{17}{18}+\dfrac{17}{14}-\dfrac{5}{7}\)
b. \(1-\dfrac{1}{2}+2-\dfrac{2}{3}+3-\dfrac{3}{4}+4-\dfrac{1}{4}-3-\dfrac{1}{3}-2-\dfrac{1}{2}-1\)
c.\(\dfrac{1}{3}.\dfrac{14}{25}-\dfrac{1}{2}:\dfrac{25}{14}\)
d. \(\dfrac{3}{7}+\dfrac{5}{13}+\dfrac{4}{7}-\dfrac{18}{13}\)
