99^20 = (99^2)^10 = 9801^10
Vì: 9801^10 < 9999^10 (9801 <9999)
=> 99^20 < 9999^10 (đpcm)

k nha bn

Ta có:

99²⁰ = (99²)¹⁰ = 9810¹⁰

Mà 9810¹⁰ < 9999¹⁰

=> 99²⁰ < 9999¹⁰

Vậy 99²⁰ < 9999¹⁰

Ta co : 9999¹⁰=(99¹⁰¹)¹⁰=99¹⁰¹⁰

Ta thấy: 99²⁰< 99¹⁰¹⁰ (Vì 20<1010)

Vậy 99²⁰<9999¹⁰⁰¹

^{Thong cam mik chi lam dc den day thoi}

Nhớ mik nha!

99²⁰ <  9999¹⁰

11¹⁹⁷⁹ < 37¹³²⁰

CHÚC BẠN HỌC TỐT. HAPPY NEW YEAR!

c,99^20=(99^2)^10=9801^10<9999^10

--------Hok tốt-------

a,2^91=2^85.2^6

         =(2^5)^17.64

         =32^17.64

  5^35=5^34.5

         =25^17.5

Có 32^17>25^17;64>5

Nên 2^91>5^35

a) 25³⁵=(5²)³⁵=5⁷⁰

125¹⁵=(5³)¹⁵=5⁴⁵<5⁷⁰=25³⁵

b/ 11³⁰=(11³)¹⁰=1331¹⁰

23²⁰=(23²)¹⁰=529¹⁰ < 1331¹⁰=11³⁰

c) 9999¹⁰ = (99.101)¹⁰ = 99¹⁰.101¹⁰> 99¹⁰.99¹⁰=99²⁰

d) 80.50⁵ = 80.5⁵.10⁵> 2.32.5⁵.10⁵=2.2⁵.5⁵.10⁵=2.10⁵.10⁵=2.10¹⁰>10¹⁰

e) 2³ⁿ=(2³)ⁿ=8ⁿ

3²ⁿ=(3²)ⁿ=9ⁿ > 8ⁿ=2³ⁿ

a) 2535

a) \(99^{20}=\left(99^2\right)^{10}=\left(99.99\right)^{10}\)

\(9999^{10}=\left(99.101\right)^{10}\)

Ta thấy \(99.100>99.99\Rightarrow\left(99.99\right)^{10}< \left(99.101\right)^{10}\Leftrightarrow99^{20}< 9999^{10}\)

b) Ta có : \(202^{303}=\left[\left(2.101\right)^3\right]^{101}=8^{101}.101^{303}\)

\(303^{202}=\left[\left(3.101\right)^2\right]^{101}=9^{101}.101^{202}\)

Tự làm tiếp nha bn

a)99²⁰ và 999¹⁰

Ta có:ƯCLN(20;10)=10

\(\Rightarrow99^{20}=\left(99^2\right)^{10}\)

\(9999^{10}=\left(9999^1\right)^{10}\)

\(99^2=9801< 9999\)

\(\Rightarrow99^{20}< 9999^{10}\)

ta co:25^35 va 125^15

        (5^2)^35 va (5^3)^15

        5^70 va 5^45

       vi 5^70 >5^45

Suy ra 25^35>125^15

minh chi lam giup ban cau dau thoi nhe! 

\(99^{20}=99^{2.10}=\left(99^2\right)^{10}=9801^{10}\)

Vì \(9801< 9999\)

Nên \(9801^{10}< 9999^{10}\)

Vậy \(99^{20}< 9999^{10}\)

\(99^{20}=99^{2.10}=\left(99^2\right)^{10}=9801^{10}\)

Vì \(9801< 9999\)

Nên \(9801^{10}< 9999^{10}\)

Vậy \(99^{20}< 9999^{10}\)