dễ mà bn , 20m

3/5 > 4/9

19/60 < 31/90

\(\frac{3}{5}\)và \(\frac{4}{9}\)

Vì \(\frac{3}{5}>\frac{3}{6}=\frac{1}{2};\frac{1}{2}=\frac{4}{8}>\frac{4}{9}\)nên \(\frac{3}{5}>\frac{4}{9}\)

\(\frac{19}{60}\)và \(\frac{31}{90}\)

Vì \(\frac{19}{60}< \frac{19}{57}=\frac{1}{3};\frac{1}{3}=\frac{31}{93}< \frac{31}{90}\)nên \(\frac{19}{60}< \frac{31}{90}\)

# Học tốt

So sánh các phân số :

                                \(\frac{3}{5}\text{ và }\frac{4}{9}\)                 \(MSC\text{ : }45\)

Ta có :

\(\frac{3}{5}=\frac{3\text{ x }9}{5\text{ x }9}=\frac{27}{45}\)                   ;                            \(\frac{4}{9}=\frac{4\text{ x }5}{9\text{ x }5}=\frac{20}{45}\)

\(\text{Vì :}\frac{27}{45}>\frac{20}{45}\text{ nên }\frac{3}{5}>\frac{4}{9}\)

                                               \(\frac{19}{60}\text{ và }\frac{31}{90}\)                      \(MSC\text{ : }180\)

Ta có :

 \(\frac{19}{60}=\frac{19\text{ x }3}{60\text{ x }3}=\frac{57}{180}\)                                ;                                     \(\frac{31}{90}=\frac{31\text{ x }2}{90\text{ x }2}=\frac{62}{180}\)

 \(\text{Vì : }\frac{57}{180}< \frac{62}{180}\text{ nên }\frac{19}{60}< \frac{31}{90}\)                           

a ) − 1 > − 2 ; b ) − 9 11 < − 8 11 ; c ) 1 6 > − 7 10 ; d ) 29 20 < 2

:((

8/12=2/3=4/6<4/5

a)5/8 < 8/9

b)8/12> 5/9

c)7/12 < 11/18

a)5/8 < 8/9

b)8/12 > 5/9

c)7/12 < 11/18

a) 5/8 < 8/9

b) 8/12 > 5/9

c) 7/12 < 11/18

a)      31/24

b)   5/6

c)     29/9 

bài 1

mik luoi lam

\(a,\dfrac{1}{7}và\dfrac{4}{5}\)

\(\dfrac{1}{7}=\dfrac{1\times5}{7\times5}=\dfrac{5}{35}\)

\(\dfrac{4}{5}=\dfrac{4\times7}{5\times7}=\dfrac{28}{35}\)

Vậy \(\dfrac{5}{35}< \dfrac{28}{35}hay\dfrac{1}{7}< \dfrac{4}{5}\)

a/

\(27^{81}=\left(3^3\right)^{81}=3^{241}\)

\(81^{27}=\left(3^4\right)^{27}=3^{108}\)

\(\Rightarrow27^{81}=3^{241}>3^{108}=81^{27}\)

b/

\(5^{60}=\left(5^3\right)^{20}=125^{20}\)

\(7^{40}=\left(7^2\right)^{20}=49^{20}\)

\(\Rightarrow5^{60}=125^{20}>49^{20}=7^{40}\)

c/

\(11^{102}=\left(11^2\right)^{51}=121^{51}>121^{50}>99^{50}\)