a) \(3^{39}\) và \(11^{21}\)

\(\Rightarrow3^{39}=3^{13.3}=1594323^3\)

\(\Rightarrow11^{21}=11^{7.3}=194487171^3\)

Nên \(3^{39}< 11^{21}\)

b) \(199^{20}\) và \(2003^{15}\)

\(\Rightarrow199^{20}=199^{4.5}=1568239201^5\)

\(\Rightarrow2003^{15}=8036054027^5\)

Nên \(199^{20}< 2003^{15}\)

339 và 1121

339< 342; 342=36.7=(36)7=7297

1121= 113.7=(113)7=13317

Vì 7297< 13317=> 342<1121

=>339<1121

CHUC HOK TOT

a) 199²⁰ < 200²⁰

2000¹⁵ < 2003¹⁵

ta có : 200²⁰ = ( 8 . 25 ) ²⁰ = ( 2³ . 5² )²⁰ = 2⁶⁰ . 5⁴⁰

 2000¹⁵ = ( 2 .10³ ) ¹⁵ =  ( 2⁴ . 5³ ) ¹⁵ = 2⁶⁰ . 5⁴⁵

Vì 40 < 45 nên 2⁶⁰ . 5⁴⁰ < 2⁶⁰ . 5⁴⁵ hay 199²⁰ < 2003¹⁵

b) 5²¹⁷ và 119⁷²

ta có : 5²¹⁷ > 5²¹⁶ = 125⁷² > 119⁷²

Vì 5²¹⁷ > 5²¹⁶ hoặc 125⁷² > 119⁷² 

nên 5²¹⁷ > 119⁷²

de thui nhung bay 

gio mk rat ban nen ko the klam

duoc luc nao ranh lam cho

chuc bn hoc gioi!

de thi hoc ki mot co cau nay do

+ Ta có \(199^{20}< 216^{20}=\left(6^3\right)^{20}=6^{60}\)

+ Ta có \(2003^{15}>1296^{15}=\left(6^4\right)^{15}=6^{60}\)

=> \(199^{20}< 2003^{15}\)

so sánh lũy thừa

a ) 

199²⁰ < 2003¹⁵

b )

3⁹⁹ > 11²¹

a) 2003^15 > 2000^15 = (2.10^3)^15 = 2^15.10^45 
199^20 < 200^20 = (2.10^2)^20 = 2^20.10^40 =2^15.2^5.10^40 <2^15.10^40.100 =2^15.10^42 
Vậy 199^20 < 2003^15

b) 3^99 > 11^21 
vì 

3^99 = (3³³)³ 
11^21 = (11^7)³ 

Còn số mũ giờ so sánh 3³³ và 11^7 

3³³ = (3^4)^7 * 3^5 
mà 3^4 > 11 

==> 3^99 > 11^21

199 mũ 20 < 2003 mũ 15

so sanh voi trung gian la 200^20=2000^15

****
 

a

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