a)  1024 9 = ( 2 10 ) 9 = 2 90 < 2 100

b)  6 . 5 29 > 5 . 5 29 = 5 30

c) 10 30 = ( 10 3 ) 10 = 1000 10 ; 2 100 = ( 2 10 ) 10 = 1024 10   n ê n   10 30 < 2 100 .

a) >

b) <

c) <

d) <

a)>

b)<

c)<

d)<

a) Cách 1:  2 100 = 2 10 10 = 1024 10 > 1024 9

Cách 2:  1024 9 = 2 10 9 =  2 90  <  2 100

b)  6 . 5 29  >  5 . 5 29  =  5 30

c)  2 98 =  2 2 49 =  4 49  <  9 49

d)  10 30 =  10 3 10 = 1000 10 ;  2 100 =  2 10 10  = 1024 10 nên  10 30  <  2 100

a) <
b) <
c) >
d) =

cảm nơn bạn nhe.

\(70-5\cdot\left(x-3\right)=45\)

\(\Rightarrow5\cdot\left(x-3\right)=70-45\)

\(\Rightarrow5\cdot\left(x-3\right)=25\)

\(\Rightarrow x-3=\dfrac{25}{5}\)

\(\Rightarrow x-3=5\)

\(\Rightarrow x=5+3=8\)

==============

\(10+2\cdot x=4^5:4^3\)

\(\Rightarrow10+2\cdot x=4^2\)

\(\Rightarrow10+2\cdot x=16\)

\(\Rightarrow2\cdot x=16-10\)

\(\Rightarrow2\cdot x=6\)

\(\Rightarrow x=\dfrac{6}{2}=3\)

=============

\(2\cdot x-138=2^3\cdot3^2\)

\(\Rightarrow2\cdot x-138=72\)

\(\Rightarrow2\cdot x=72+138\)

\(\Rightarrow2\cdot x=210\)

\(\Rightarrow x=\dfrac{210}{2}=105\)

==============

\(231-\left(x-6\right)=1339:12\)

\(\Rightarrow231-x+6=1339:12\)

\(\Rightarrow237-x=\dfrac{1339}{12}\)

\(\Rightarrow x=237-\dfrac{1339}{12}\)

\(\Rightarrow x=\dfrac{1505}{12}\)

a: 43/52>26/52=1/2=60/120

b: 17/68=1/4<1/3=35/105<35/103

c: \(\dfrac{2018\cdot2019-1}{2018\cdot2019}=1-\dfrac{1}{2018\cdot2019}\)

\(\dfrac{2019\cdot2020-1}{2019\cdot2020}=1-\dfrac{1}{2019\cdot2020}\)

2018*2019<2019*2020

=>-1/2018*2019<-1/2019*2020

=>\(\dfrac{2018\cdot2019-1}{2018\cdot2019}< \dfrac{2019\cdot2020-1}{2019\cdot2020}\)

\(\dfrac{19}{19}\) = 1 < \(\dfrac{2005}{2004}\) vậy \(\dfrac{19}{19}\) < \(\dfrac{2005}{2004}\)

\(\dfrac{72}{73}\) = 1 - \(\dfrac{1}{73}\) 

\(\dfrac{98}{99}\) = 1 - \(\dfrac{1}{99}\)

Vì \(\dfrac{1}{73}\) > \(\dfrac{1}{99}\) nên \(\dfrac{72}{73}\) < \(\dfrac{98}{99}\) 

1) 19/19 < 2005/2004

2)72/73 > 98/99

a) ta có:  \(1-\frac{2012}{2013}=\frac{1}{2013}\)

                 \(1-\frac{2013}{2014}=\frac{1}{2014}\)

mà \(\frac{1}{2013}>\frac{1}{2014}\) nên   \(\frac{2013}{2014}>\frac{2012}{2013}\)

sao giống lớp 4 thế ta

2²²⁵ = (2³)⁷⁵ = 8⁷⁵

3¹⁵¹ > 3¹⁵⁰ = (3²)⁷⁵ = 9⁷⁵

=> 3¹⁵¹ > 9⁷⁵ > 8⁷⁵

=> 3¹⁵¹ > 2²²⁵

4n - 5 chia hết cho 2n - 1

=> 4n - 2 - 3 chia hết cho 2n - 1

=> 2.(2n - 1) - 3 chia hết cho 2n - 1

Do 2.(2n - 1) chia hết cho 2n - 1 => 3 chia hết cho 2n - 1

Mà n thuộc N => 2n - 1 > hoặc = -1

=> 2n - 1 thuộc {-1 ; 1 ; 3}

=> 2n thuộc {0 ; 2 ; 4}

=> n thuộc {0 ; 1 ; 2}