Question

Sắp xếp các phân số theo thứ tự tăng dần :

\(\dfrac{-1}{2};\dfrac{5}{12};\dfrac{7}{18};\dfrac{-5}{9};\dfrac{-1}{3};\dfrac{1}{3}\)

Answer 1

\(\dfrac{-1}{2}=\dfrac{-9}{18};\dfrac{-5}{9}=\dfrac{-10}{18};\dfrac{-1}{3}=\dfrac{-6}{18}\)

mà -10<-9<-6<0

nên \(-\dfrac{5}{9}< -\dfrac{1}{2}< -\dfrac{1}{3}< 0\)(1)

Ta có: \(\dfrac{5}{12}=\dfrac{15}{36};\dfrac{7}{18}=\dfrac{14}{36};\dfrac{1}{3}=\dfrac{12}{36}\)

mà \(0< \dfrac{12}{36}< \dfrac{14}{36}< \dfrac{15}{36}\)

nên \(0< \dfrac{1}{3}< \dfrac{7}{18}< \dfrac{5}{12}\left(2\right)\)

Từ (1),(2) suy ra \(-\dfrac{5}{9}< -\dfrac{1}{2}< -\dfrac{1}{3}< \dfrac{1}{3}< \dfrac{7}{18}< \dfrac{5}{12}\)