\(=\frac{16}{5}.\frac{15}{16}-\left(\frac{3}{4}+\frac{2}{7}\right):\left(\frac{-29}{28}\right)\)

\(=3-\left(\frac{21}{28}+\frac{8}{28}\right):\left(\frac{-29}{28}\right)\)

\(=3-\left(\frac{29}{28}\right).\left(\frac{-28}{29}\right)\)

\(=3-\left(-1\right)\)

\(=4\)

b)   \(=\left(\frac{1}{4}+\frac{25}{2}-\frac{5}{16}\right):\left(12-\frac{7}{12}:\left(\frac{3}{8}-\frac{1}{12}\right)\right)\)

       \(=\left(\frac{4}{16}+\frac{200}{16}-\frac{5}{16}\right):\left(12-\frac{7}{12}:\left(\frac{3.3}{2.3.4}-\frac{2}{2.3.4}\right)\right)\)

     \(=\left(\frac{199}{16}\right):\left(12-\frac{7}{12}:\left(\frac{9}{24}-\frac{2}{24}\right)\right)\)

      \(=\frac{199}{16}:\left(12-\frac{7}{12}.\frac{24}{7}\right)\)

    \(=\frac{199}{16}:\left(12-2\right)\)

\(=\frac{199}{16}:10\)

\(=\frac{199}{160}\)

c)   \(\left(\frac{-3}{5}+\frac{5}{11}\right):\frac{-3}{7}+\left(\frac{-2}{5}+\frac{6}{5}\right):\frac{-3}{7}\)

\(\left(\frac{-33}{55}+\frac{25}{55}\right):\frac{-3}{7}+\left(\frac{4}{5}\right):\frac{-3}{7}\)

\(\left(\frac{-8}{55}\right).\frac{-7}{3}+\frac{4}{5}.\frac{-7}{3}\)

\(\frac{-7}{3}\left(\frac{-8}{55}+\frac{4}{5}\right)\)

\(\frac{-7}{3}.\frac{36}{55}=\frac{-84}{55}\)

giờ mk phải đi ngủ r mai mk làm cho 

nhớ làm giúp mình nhá mai mình phải đi học r :<

\(a)x+30\%x=-1,31\)

\(\Leftrightarrow x+\frac{3x}{10}=-1,31\)

\(\Leftrightarrow10x+3x=-13,1\)

\(\Leftrightarrow13x=-13,1\Leftrightarrow x=-\frac{131}{130}\)

\(b)\left(x-\frac{1}{2}\right):\frac{1}{3}+\frac{5}{7}=9\frac{5}{7}\)

\(\Leftrightarrow\frac{2x-1}{2}.3+\frac{5}{7}=\frac{68}{7}\)

\(\Leftrightarrow\frac{6x-3}{2}=\frac{63}{7}\)

\(\Leftrightarrow\frac{6x-3}{2}=9\)

\(\Leftrightarrow6x-3=18\)

\(\Leftrightarrow x=\frac{7}{2}\)

\(c)\frac{1}{2}x-\frac{3}{4}=\frac{14}{9}.\frac{3}{7}\)

\(\Leftrightarrow\frac{x}{2}-\frac{3}{4}=\frac{2}{3}\)

\(\Leftrightarrow\frac{x}{2}=\frac{17}{12}\)

\(\Leftrightarrow12x=34\Leftrightarrow x=\frac{17}{6}\)

x=1,375

x=1,375

\(\left(4,5-2x\right).\frac{11}{7}=\frac{11}{14}\)

\(4,5-2x=\frac{11}{14}.\frac{7}{11}=\frac{1}{2}\)

\(2x=\frac{1}{2}-4,5=-4\)

\(x=\left(-4\right):2=-2\)

a) 2/3 x = 2/9 + 4/9

=> 2/3 x = 2/3

=> x = 1

b) 4,5 - 2x = 11/14 + \(-1\frac{4}{7}\)

=> 4,5 - 2x = 5/14

=> 2x = 4,5 - 5/14

=> 2x = 29/7

=> x= 29/14

\(\left(2,8x-32\right)\div\frac{2}{3}=-90\)

\(\Rightarrow2,8x-32=-60\)

\(\Rightarrow2,8x=-28\)

\(\Rightarrow x=-10\)

\(\left(4,5-2x\right)\times1\frac{4}{7}=\frac{11}{14}\)

\(\Rightarrow4,5-2x=\frac{1}{2}\)

\(\Rightarrow2x=4\)

\(\Rightarrow x=2\)

a, \(\frac{3}{5}-\left(\frac{3}{5}+x\right)=\frac{2}{7}\)

\(\frac{3}{5}-\frac{3}{5}-x=\frac{2}{7}\)

\(-x=\frac{2}{7}\)

\(\Rightarrow x=-\frac{2}{7}\)

b, \(\frac{3}{7}+\frac{1}{7}:x=\frac{3}{14}\)

\(\frac{1}{7}:x=\frac{3}{14}-\frac{3}{7}=\frac{3}{14}-\frac{6}{14}=-\frac{3}{14}\)

 \(x=\frac{1}{7}:-\frac{3}{14}=-\frac{2}{3}\)

tu lam con cu thich di hoi

\(\left[\left(35\frac{5}{7}+2\frac{3}{4}\right)-5\frac{5}{7}+\frac{1}{4}\right]:\left(11+x\right)=3\)

\(\left[\left(35\frac{5}{7}-5\frac{5}{7}\right)+2\frac{3}{4}+\frac{1}{4}\right]:\left(11+x\right)=3\)

\(\left[30+3\right]:\left(11+x\right)=3\)

\(33:\left(11+x\right)=3\)
\(11+x=11\)

\(x=0\)

\(\left[\left(35\frac{5}{7}+2\frac{3}{4}\right)-5\frac{5}{7}+\frac{1}{4}\right]\div\left(11+x\right)=3\)

\(\left[\left(\frac{35\times7+5}{7}+\frac{2\times4+3}{4}\right)-\frac{5\times7+5}{7}+\frac{1}{4}\right]\div\left(11+x\right)=3\)

\(\left[\left(\frac{250}{7}+\frac{11}{4}\right)-\frac{40}{7}+\frac{1}{4}\right]\div\left(11+x\right)=3\)

\(\left[\frac{1077}{28}-\frac{167}{28}\right]\div\left(11+x\right)=3\)

\(32,5\div\left(11+x\right)=3\)

\(11+x=32,5\div3\)

\(11+x=\frac{65}{6}\)

\(x=\frac{65}{6}-11=-\frac{1}{6}\)

\(\Rightarrow\left[\left(\frac{250}{7}+\frac{11}{4}\right)-\frac{40}{7}+\frac{1}{4}\right]:\left(11+x\right)=3\)

\(\Rightarrow\left(\frac{1000}{28}+\frac{77}{28}-\frac{160}{28}+\frac{7}{28}\right):\left(11+x\right)=3\)

\(\Rightarrow33:\left(11+x\right)=3\)

\(\Rightarrow11+x=11\)

\(\Rightarrow x=0\)