Question

Bài 3: So Sánh

a)\(\dfrac{13}{17}\)và\(\dfrac{25}{29}\)

b)\(\dfrac{59}{101}\)và\(\dfrac{56}{105}\)

c)\(\dfrac{14}{55}\)và\(\dfrac{20}{83}\)

d)\(\dfrac{13}{57}\)và\(\dfrac{29}{73}\)

e)\(\dfrac{17}{21}\)và\(\dfrac{1717}{2121}\)

Answer 1

a,

\(\dfrac{13}{17}=1-\dfrac{4}{17}\\ \dfrac{25}{29}=1-\dfrac{4}{29}\\ \dfrac{4}{17}>\dfrac{4}{29}\Rightarrow1-\dfrac{4}{17}< 1-\dfrac{4}{29}\Leftrightarrow\dfrac{13}{17}< \dfrac{25}{29}\)

Vậy \(\dfrac{13}{17}< \dfrac{25}{29}\)

b,

\(\dfrac{59}{101}>\dfrac{56}{101}>\dfrac{56}{105}\\ \Rightarrow\dfrac{59}{101}>\dfrac{56}{105}\)

Vậy \(\dfrac{59}{101}>\dfrac{56}{105}\)

c,

\(\dfrac{14}{55}>\dfrac{14}{56}=\dfrac{1}{4}=\dfrac{20}{80}>\dfrac{20}{83}\)

Vậy \(\dfrac{14}{55}>\dfrac{20}{83}\)

Answer 2

d,

\(\dfrac{13}{57}< \dfrac{13}{39}=\dfrac{1}{3}=\dfrac{29}{87}< \dfrac{29}{73}\)

Vậy \(\dfrac{13}{57}< \dfrac{29}{73}\)

e,

\(\dfrac{17}{21}=\dfrac{17\cdot101}{21\cdot101}=\dfrac{1717}{2121}\)

Vậy \(\dfrac{17}{21}=\dfrac{1717}{2121}\)