Bài 4:
a: \(\frac{-5}{9}+\frac35-\frac39+\frac{-2}{5}\)
\(=\left(\frac35-\frac25\right)-\left(\frac59+\frac39\right)\)
\(=\frac15-\frac89=\frac{9-40}{45}=\frac{-31}{45}\)
b: \(\frac{5}{17}-\frac{9}{15}-\frac{2}{17}+\frac{-2}{5}\)
\(=\left(\frac{5}{17}-\frac{2}{17}\right)-\left(\frac35+\frac25\right)\)
\(=\frac{3}{17}-1=-\frac{14}{17}\)
c: \(\frac{-5}{13}-\left(\frac35+\frac{3}{13}-\frac{4}{10}\right)\)
\(=\frac{-5}{13}-\frac35-\frac{3}{13}+\frac{4}{10}=\frac{-8}{13}-\frac{6}{10}+\frac{4}{10}\)
\(=-\frac{8}{13}-\frac15=\frac{-40-13}{65}=\frac{-53}{65}\)
d: \(\left(\frac19-\frac{9}{17}\right)+\frac36-\left(\frac{12}{17}-\frac12\right)+\frac59\)
\(=\frac19+\frac59-\frac{9}{17}+\frac12-\frac{12}{17}+\frac12\)
\(=\frac69+1-\frac{21}{17}=\frac23-\frac{4}{17}=\frac{34-12}{51}=\frac{22}{51}\)
Bài 5:
a: \(\frac{-31}{23}-\left(\frac{7}{32}-\frac{8}{23}\right)\)
\(=-\frac{31}{23}-\frac{7}{32}+\frac{8}{23}=-1-\frac{7}{32}=\frac{-39}{32}\)
b: \(\frac{38}{45}-\left(\frac{8}{45}-\frac{17}{51}-\frac{3}{11}\right)\)
\(=\frac{38}{45}-\frac{8}{45}+\frac13+\frac{3}{11}\)
\(=\frac{30}{45}+\frac13+\frac{3}{11}=\frac{3}{11}+1=\frac{14}{11}\)
c: \(\left(\frac13+\frac{12}{67}+\frac{13}{41}\right)-\left(\frac{79}{67}-\frac{28}{41}\right)\)
\(=\frac13+\frac{12}{67}+\frac{13}{41}-\frac{79}{67}+\frac{28}{41}=\frac13+\left(\frac{12}{67}-\frac{79}{67}\right)+\left(\frac{13}{41}+\frac{28}{41}\right)\)
\(=\frac13-1+1=\frac13\)
d: \(\frac{7}{12}-\left(\frac16+\frac{5}{12}\right)\)
\(=\frac{7}{12}-\frac16-\frac{5}{12}=\frac16-\frac16\)
=0
