\(a,\left(9,75.21\frac{3}{7}+\frac{39}{4}.18\frac{4}{7}\right).\frac{15}{78}\)

\(b,\frac{-7}{21}+\left(1+\frac{1}{3}\right)\) \(c,\frac{2}{15}+\left(\frac{5}{9}+\frac{-6}{9}\right)\)

\(d,\left(\frac{-1}{5}+\frac{3}{12}\right)+\frac{-3}{4}\)

\(e,\frac{4}{20}+\frac{16}{42}+\frac{6}{15}+\frac{-3}{5}+\frac{2}{21}+\frac{-10}{21}+\frac{3}{20}\)

\(\left(20+9\frac{1}{4}\right):2\frac{1}{4}\) \(\left(6-2\frac{4}{5}\right).3\frac{1}{8}-1\frac{3}{5}:\frac{1}{4}\)

\(\frac{32}{15}:\left(-1\frac{1}{5}+1\frac{1}{3}\right)\) \(0,2.\frac{15}{36}-\left(\frac{2}{5}=\frac{2}{3}\right):1\frac{1}{5}\)

\(\frac{-3}{7}.\frac{5}{9}+\frac{4}{9}.\frac{-3}{7}+2\frac{3}{7}\) \(0,7.2\frac{2}{3}.20.0,375.\frac{5}{8}\)

1, tim x bết:

,\(\frac{\left(-5^4\right).\left(-15^2\right)-5^4.\left(-3^2.5\right)}{\left(-3^4\right).25^2-\left(-15^2\right).225.5}\)\(:\)\(\frac{x}{5}\)\(=\frac{-1}{6}\)

2, cho A=\(\frac{20}{30}+\frac{20}{70}+\frac{20}{126}+...+\frac{20}{798}\)

B=\(\left(\frac{41}{2}.\frac{42}{2}.\frac{43}{2}...\frac{80}{2}\right):\left(1.3.5...79\right)\)

So sánh A và B.

3, Tính nhanh.

\(\frac{0,875+\frac{1}{2}-7\%-\frac{1}{58}}{\frac{1}{25}-\frac{1}{2}-\frac{2}{7}+\frac{2}{203}}\)\(-125\%\)

HELP  ME  PLEASE......

\(a,1\frac{13}{15}.0,75-\left(\frac{8}{15}+0,25\right).\frac{24}{47}\)

\(b,5:\left(4\frac{3}{4}-1\frac{25}{28}\right)-1\frac{3}{8}:\left(\frac{3}{8}+\frac{9}{20}\right)\)

\(c,6\frac{5}{12}:2\frac{3}{4}+11\frac{1}{4}.\left(\frac{1}{3}-\frac{1}{5}\right)\)

\(d,\left(\frac{3}{5}+0,415-\frac{3}{200}\right).2\frac{2}{3}.0,25\)

\(e,\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)

\(g,1\frac{13}{15}.0,75-\left(\frac{11}{20}+25\%\right);\frac{7}{3}\)

Tìm x, biết:

a)\(\frac{x}{5}\)= \(\frac{2}{3}\)

b)\(\frac{x}{-24}\) = \(\frac{20}{40}\) 

c)\(\frac{x+3}{15}\) = \(\frac{1}{3}\) 

d)\(\frac{2}{3}.x-\frac{3}{2}.x=\frac{5}{12}\)

e)\(\frac{-2}{3}.x+\frac{1}{5}.x-\frac{3}{10}=0\)

f)\(\frac{-2}{3}-\frac{1}{3}.\left(2.x-5\right)=\frac{3}{2}\)

g)\(\frac{1}{3}.x+\frac{2}{5}\left(x-1\right)=0\)

Tính:

A=\(\left(1-\frac{2}{3}+\frac{4}{3}\right)-\left(\frac{4}{5}-1\right)+\left(\frac{7}{5}+2\right)\)

B=\(\left(-3+\frac{3}{4}-\frac{1}{3}\right):\left(5+\frac{2}{5}-\frac{2}{3}\right)\)

C=\(\left(\frac{3}{5}-\frac{4}{15}\right).\left(\frac{2}{7}-\frac{3}{14}\right)-\left(\frac{5}{9}-\frac{7}{27}\right)\)\(.\left(1-\frac{3}{5}\right)+\left(1-\frac{11}{12}\right).\left(1+\frac{11}{12}\right)\)

D=\(\frac{\left(\frac{3}{10}-\frac{4}{15}-\frac{7}{20}\right).\frac{-5}{19}}{\left(\frac{1}{14}+\frac{1}{7}-\frac{-3}{35}\right).\frac{4}{3}}\)

12)\(0,2.\frac{15}{36}-\left(\frac{2}{5}+\frac{2}{3}\right):1\frac{1}{5}\)

13)\(1\frac{13}{15}.0,75-\left(\frac{8}{15}+0,25\right).\frac{24}{27}\)

16)\(\frac{1}{2}+\frac{3}{4}-\left(\frac{3}{4}-\frac{4}{5}\right).\left(-2,75\right)\)

18)\(\left(\frac{7}{8}-\frac{3}{4}\right).1\frac{1}{3}-\frac{2}{7}.\left(3.5\right)^2\)

22)\(1\frac{13}{15}.0,75-\left(\frac{11}{20}+25\%\right):\frac{7}{3}\)

23)\(\frac{\left(\frac{2}{3}-0,75\right).\left(0,2-\frac{2}{5}\right)}{\frac{5}{9}-1\frac{1}{12}}\)

33)\(\left(25\%+\frac{1}{3}+0,75\right):\left(4\frac{3}{4}-3\frac{1}{2}\right)\)

35)\(\left(\frac{377}{-231}-\frac{123}{89}+\frac{34}{791}\right).\left(\frac{1}{6}-\frac{1}{8}-\frac{1}{24}\right)\)