a)2^31=2.2^30=2.8^10

3^21=3.3^20=3.9^10

Vì 2.8^10<3.^10

\(\Rightarrow\)28^10<3.9^10\(\Rightarrow\)2^31<3^21

b)3^39=3^\(^{13x3}\)=159323^3

11^21=11\(^{7x3}\)=19487171^3

Vì 159323^3<19487171^3\(\Rightarrow\)3^39<11^21

c)11^1979<37^1320=(11^3)^660=1331^660

37^1320=(37^2)^660\(\Rightarrow\)11^1979<37^1320

hehe lm bừa

à chết nhìn lộn đúng òi bn

song ngu sai bét

32

có giỏi thì lm đi

ƯCLN ( 123456789 ; 987654321 )

123456789 = 3² . 13717421

987654321 = 3² . 109739369                                                    

Vậy UCLN ( 123456789 ; 987654321 ) = 3² = 9              
 

64=1x8x8=1x8x4x2=1,248