Question

sắp xếp các phân số sau theo thứ tự giảm dần

\(\dfrac{73}{72}\) ; \(\dfrac{43}{42}\) ; \(\dfrac{53}{52}\); \(\dfrac{65}{64}\); \(\dfrac{87}{86}\)

Answer 1

\(\dfrac{73}{72}=1+\dfrac{1}{72}\)

\(\dfrac{43}{42}=1+\dfrac{1}{42}\)

\(\dfrac{53}{52}=1+\dfrac{1}{52}\)

\(\dfrac{65}{64}=1+\dfrac{1}{64}\)

\(\dfrac{87}{86}=1+\dfrac{1}{86}\)

mà \(\dfrac{1}{42}>\dfrac{1}{52}>\dfrac{1}{64}>\dfrac{1}{72}>\dfrac{1}{86}\left(42< 52< 64< 72< 86\right)\)

nên \(\dfrac{43}{42}>\dfrac{53}{52}>\dfrac{65}{64}>\dfrac{73}{72}>\dfrac{87}{86}\)