b3 tính nhanh nếu có thể
a \(\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}\)
b \(\frac{1}{2}\cdot\frac{1}{2}+\frac{1}{2}\cdot\frac{1}{3}+\frac{1}{3}\cdot\frac{1}{4}+\frac{1}{4}\cdot\frac{1}{5}+\frac{1}{5}\cdot\frac{1}{6}\)
c\(1\frac{1}{24}\cdot5\frac{2}{5}\cdot2-3\frac{7}{9}\cdot2\frac{2}{17}\)
d\(2\frac{3}{13}\cdot\frac{26}{58}\cdot4\cdot2\frac{15}{24}\cdot\frac{8}{21}\)
e \(\left(1-\frac{6}{11}\right)-\frac{5}{11}\)
f\(\left(\frac{15}{7}-\frac{2}{3}\right)+\frac{2}{3}\)
g\(\left(\frac{5}{8}-\frac{1}{4}\right)+\frac{3}{8}\)
\(h\frac{3}{3\cdot5}+\frac{3}{5\cdot8}+\frac{3}{8\cdot11}+\frac{3}{11\cdot14}+\frac{3}{14\cdot17}+\frac{3}{17\cdot20}\)
bài 1:thực hiện phép tính :
a)\(\frac{3}{7}+\frac{5}{13}+\frac{4}{13}\)
b)\(\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)
c)\(\frac{2}{5}.\frac{1}{3}-\frac{2}{15}:\frac{1}{5}+\frac{3}{5}.\frac{1}{3}\)
d)\(\left(4-\frac{5}{12}\right):2+\frac{5}{24}\)
e)\(\frac{7}{19}.\frac{8}{11}+\frac{3}{11}.\frac{7}{19}+\frac{-1}{19}\)
f)\(\frac{9}{27}+\frac{8}{24}+\frac{18}{27}-\frac{-16}{24}+\frac{2}{3}\)
g)\(\frac{-5}{21}+\frac{-2}{21}+\frac{8}{24}\)
h)\(\frac{-5}{9}+\frac{8}{15}+\frac{-2}{11}+\frac{4}{-9}+\frac{7}{15}\)
i)\(\frac{7}{25}.\frac{39}{-14}.\frac{50}{78}\)
m.n làm nhanh cho mình nhé, chiều mình phải nộp rồi! cảm ơn m.n!
Câu 1:
*LƯU Ý: dấu này"." là nhân.
a) \(57\%+1\frac{2}{15}:\frac{68}{25}-2.282\)
b) \(1\frac{13}{15}.0,75-\left(\frac{8}{15}+0,25\right).\frac{24}{47}\)
c) \(\frac{3}{4}.\frac{16}{9}-\frac{7}{5}:\frac{-21}{26}\)
d) \(5:\left(4\frac{3}{4}-1\frac{25}{28}\right)-1\frac{3}{8}:\left(\frac{3}{8}-\frac{9}{20}\right)\)
CÁC BẠN ƠI GIÚP MÌNH VOIỨ MAI MK NỘP CHO CÔ RÙI HUHU
Tính \(6.\frac{-5}{18};\frac{-13}{24}+\frac{-5}{21}.\frac{7}{25};\frac{-5}{3}-\frac{3}{26}.\frac{-2}{3};\)
Tính giá trị biểu thức
1, \(\frac{1}{16}-\frac{5}{21}+\left(\frac{-1}{16}+\frac{-3}{5}-\frac{-5}{21}\right)+\frac{-2}{3}+\frac{3}{4}\)
2, \(\left(\frac{5}{8}-\frac{4}{13}+\frac{3}{2}\right)-\left(\frac{5}{8}+\frac{9}{13}\right)-\left|\frac{-3}{2}\right|+\frac{-7}{15}\)
Tính nhanh :
\(\frac{-3}{7}+\frac{15}{26}-\left(\frac{2}{13}-\frac{3}{7}\right)\)
\(2.\frac{3}{7}+\left(\frac{2}{9}-1\frac{3}{7}\right)-\frac{5}{3}:\frac{1}{9}\)
\(\frac{-11}{23}.\frac{6}{7}+\frac{8}{7}.\frac{-11}{23}-\frac{1}{23}\)
\(\left(\frac{377}{-231}-\frac{123}{89}+\frac{34}{791}\right).\left(\frac{1}{6}-\frac{1}{8}-\frac{1}{24}\right)\)
\(\frac{6}{13}-\frac{3}{26}\)
\(\frac{15}{12}+\frac{6}{24}\)
Câu 1: Chứng tỏ rằng:
\(\frac{1}{20}+\frac{1}{21}+\frac{1}{22}+...+\frac{1}{26}+\frac{1}{27}>\frac{8}{27}\)
Câu 2: Tính:
\(D=\frac{2^{10}.6^{15}+3^{14}.15.4^{13}}{2^{18}.18^7.3^3+3^{15}.2^{25}}\)
So sánh\(\frac{1}{2}+\frac{1}{13}+\frac{1}{14}+\frac{1}{15}+\frac{1}{22}+\frac{1}{23}+\frac{1}{24}+\frac{1}{25}+\frac{1}{26}\)và 1