Question

Bài 4 : Quy đồng mẫu các phân số rồi sắp xếp theo thứ tự tăng dần :

a) \(\frac{15}{-50}\); \(\frac{7}{10}\); \(\frac{24}{-20}\)

b) \(\frac{17}{39}\); \(\frac{11}{65}\); \(\frac{9}{52}\)

c) \(\frac{17}{20}\); \(\frac{-19}{30}\); \(\frac{38}{45}\); \(\frac{-13}{18}\)

Answer 1

a/ \(\frac{15}{-50}=-\frac{3}{10}\)

\(\frac{7}{10}\)

\(\frac{24}{-20}=-\frac{12}{10}\)

\(\Rightarrow-\frac{12}{10};-\frac{3}{10};\frac{7}{10}\)

KL: ..........................................

b/ \(\frac{17}{39}=\frac{17.20}{39.20}=\frac{340}{780}\)

\(\frac{11}{65}=\frac{11.12}{65.12}=\frac{132}{780}\)

\(\frac{9}{52}=\frac{9.15}{52.15}=\frac{135}{780}\)

\(\Rightarrow\frac{132}{780};\frac{135}{780};\frac{340}{780}\)

KL:.............................................

c/ \(\frac{17}{20}=\frac{17.9}{20.9}=\frac{153}{180}\)

\(\frac{-19}{30}=-\frac{19.6}{30.6}=-\frac{114}{180}\)

\(\frac{38}{45}=\frac{38.4}{45.4}=\frac{152}{180}\)

\(\frac{-13}{18}=-\frac{13.10}{18.10}=-\frac{130}{180}\)

\(\Rightarrow-\frac{130}{180};-\frac{114}{180};\frac{152}{180};\frac{153}{180}\)

KL:..................................