`5/6....4/5`
`5/6=(5xx5)/(6xx5)=25/30`
`4/5=(4xx6)/(5xx6)=24/30`
Vì `25>24` nên `5/6>4/5`
__
`2/5...12/20`
`12/20=(12:4)/(20:4)=3/5`
Vì `2<3` nên `2/5<12/20`
__
`5/12....3/4`
`3/4=(3xx3)/(4xx3)=9/12`
Vì `5<9` nên `5/12<3/4`
b: \(\dfrac{5}{6}=\dfrac{5\cdot5}{6\cdot5}=\dfrac{25}{30}\)
\(\dfrac{4}{5}=\dfrac{4\cdot6}{5\cdot6}=\dfrac{24}{30}\)
mà 25>24
nên 5/6>4/5
c: \(\dfrac{3}{5}=\dfrac{3\cdot4}{5\cdot4}=\dfrac{12}{20}\)
d: \(\dfrac{3}{4}=\dfrac{3\cdot3}{4\cdot3}=\dfrac{9}{12}>\dfrac{5}{12}\)
a) \(\dfrac{5}{6}=\dfrac{5\times5}{6\times5}=\dfrac{25}{30}\)
\(\dfrac{4}{5}=\dfrac{4\times6}{5\times6}=\dfrac{24}{30}\)
và \(\dfrac{25}{30}>\dfrac{24}{30}\Rightarrow\dfrac{5}{6}>\dfrac{4}{5}\)
b) \(\dfrac{12}{20}=\dfrac{12:4}{20:4}=\dfrac{3}{5}\)
và \(\dfrac{3}{5}=\dfrac{3}{5}\Rightarrow\dfrac{3}{5}=\dfrac{12}{20}\)
c) \(\dfrac{3}{4}=\dfrac{3\times3}{4\times3}=\dfrac{9}{12}\)
và \(\dfrac{5}{12}< \dfrac{9}{12}\Rightarrow\dfrac{5}{12}< \dfrac{3}{4}\)
#Toru