có thể sai do chữ bạn nó khó nhìn quá, ko rõ chữ
\(6,\dfrac{11}{5}-\left(x-\dfrac{+3}{8}\right)=-\dfrac{11}{40}\\ \rightarrow x-\dfrac{+3}{8}=\dfrac{11}{5}-\dfrac{-11}{40}\\ x-\dfrac{3}{8}=\dfrac{11}{5}+\dfrac{11}{40}\\ x-\dfrac{3}{8}=\dfrac{99}{40}\\ x=\dfrac{99}{40}+\dfrac{3}{8}\\ x=\dfrac{57}{20}\)
\(7,\dfrac{3}{4}+\left(x+\dfrac{4}{5}\right)=-\dfrac{11}{20}\\ x+\dfrac{4}{5}=-\dfrac{11}{20}-\dfrac{3}{4}\\ x+\dfrac{4}{5}=-\dfrac{13}{10}\\ x=-\dfrac{13}{10}-\dfrac{4}{5}\\ x=-\dfrac{21}{10}\)
\(8,\dfrac{4}{9}-\left(1\dfrac{3}{8}-x\right)=\dfrac{5}{72}\\ \dfrac{4}{9}-\left(\dfrac{11}{8}-x\right)=\dfrac{5}{72}\\ \dfrac{11}{8}-x=\dfrac{4}{9}-\dfrac{5}{72}\\ \dfrac{11}{8}-x=\dfrac{3}{8}\\ x=\dfrac{11}{8}-\dfrac{3}{8}\\ x=1\)
\(9.0,75+\left(\dfrac{7}{5}+x\right)=-1\dfrac{1}{5}\\ \dfrac{3}{4}+\left(\dfrac{7}{5}+x\right)=-\dfrac{6}{5}\\ \dfrac{7}{5}+x=-\dfrac{6}{5}-\dfrac{3}{4}\\ \dfrac{7}{5}+x=-\dfrac{39}{20}\\ x=-\dfrac{39}{20}-\dfrac{7}{5}\\ x=-\dfrac{67}{20}\)
6.
\(\Leftrightarrow\dfrac{11}{5}-x+\dfrac{3}{8}=-\dfrac{11}{40}\)
\(\Leftrightarrow\dfrac{11}{5}-x=\dfrac{11}{40}-\dfrac{3}{8}\\ \Leftrightarrow\dfrac{11}{5}-x=-\dfrac{1}{10}\\ \Leftrightarrow x=\dfrac{11}{5}+\dfrac{1}{10}\\ \Leftrightarrow x=\dfrac{23}{10}\)
7.
\(\Leftrightarrow\dfrac{3}{4}+x+\dfrac{4}{5}=-\dfrac{11}{20}\\ \Leftrightarrow\dfrac{3}{4}+x=-\dfrac{11}{20}-\dfrac{4}{5}\\ \Leftrightarrow\dfrac{3}{4}+x=-\dfrac{27}{20}\\ \Leftrightarrow x=\dfrac{-27}{20}-\dfrac{3}{4}\\ \Leftrightarrow x=\dfrac{-21}{10}\)
8.
\(\Leftrightarrow\dfrac{4}{9}-\dfrac{11}{8}+x=\dfrac{5}{72}\\ \Leftrightarrow\dfrac{-67}{72}+x=\dfrac{5}{72}\\ \Leftrightarrow x=\dfrac{5}{72}+\dfrac{67}{72}\\ \Leftrightarrow x=1\)
9.
\(\Leftrightarrow\dfrac{3}{4}+\dfrac{7}{5}+x=-\dfrac{6}{5}\\ \Leftrightarrow\dfrac{43}{20}+x=-\dfrac{6}{5}\\ \Leftrightarrow x=\dfrac{43}{20}+\dfrac{6}{5}\\ \Leftrightarrow x=\dfrac{67}{20}\)
