b)Ta có:

 \(3^{99}>3^{93}=\left(3^3\right)^{21}=27^{21}\)

Vì \(27^{21}>11^{21}\) nên \(3^{99}>27^{21}>11^{21}\) hay \(3^{99}>11^{21}\)

a) Ta có:

199²⁰ < 200²⁰ = 200¹⁵.200⁵

2003¹⁵ > 2000¹⁵ = 200¹⁵.10¹⁵ = 200¹⁵.(10³)⁵ = 200¹⁵.1000⁵

Vì 199²⁰ < 200¹⁵.200⁵ < 200¹⁵.1000⁵ < 2003¹⁵

=> 199²⁰ < 2003¹⁵

b) Ta có:

3⁹⁹ = (3³)³³ = 27³³ > 11²¹

=> 3⁹⁹ > 11²¹

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

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

****
 

Ta có:

199^20 < 200^20 = 200^15.200^5

2003^15 > 2000^15 = 200^15.10615 = 200^15.(10^3)^5 = 200^15.1000^5

Vì 199^20 < 200^15.200^5 < 200^15.1000^5 < 2003^15

=> 199^20 < 2003^15

199^20=(199^2)^10=39601^10

=>tu bt

              Giải :

Ta có dãy tính sau : 199²⁰ < 2⁶⁰ . 5⁴⁰ < 2⁶⁰ . 5⁴⁵ < 2003¹⁵

=> 199²⁰ < 2003¹⁵ .

Chúc bạn hok tốt !