Ta có: (+)  (1/32)^7   =  [(1/2)^5]^7   =(1/2)^35

          (+)  (1/16)^9=    [(1/2)^4]^9   =(1/2)^36

          Vì 35 <36

   => (1/2)^35 > (1/2)^36

  => (1/32)^7 > (1/16)^9

Bài Toán khó đây

Ta có  (2¹ -1)(2¹ + 1) = 2² - 1 

(2² - 1)(2² + 1) = 2⁴ - 1 

tương tự như vậy ta sẽ có (2 -1)A = 2³² - 1 

vậy A < 2³²

B = 1/1.2 + 1/3.4 + 1/5.6 + ... + 1/59.60

B = 1 - 1/2 + 1/3 - 1/4 + 1/5 - 1/6 + ... + 1/59 - 1/60

B = (1 + 1/3 + 1/5 + ... + 1/59) - (1/2 + 1/4 + 1/6 + ... + 1/60)

B = (1 + 1/2 + 1/3 + 1/4 + 1/5 + 1/6 + ... + 1/59 + 1/60) - 2.(1/2 + 1/4 + 1/6 + ... + 1/60)

B = (1 + 1/2 + 1/3 + 1/4 + 1/5 + 1/6 + ... + 1/59 + 1/60) - (1 + 1/2 + 1/3 + ... + 1/30)

B = 1/31 + 1/32 + 1/33 + ... + 1/60 = A

=> B = A

ta có: Lớn nhất của A là:\(\frac{1}{31}+\frac{1}{31}+...+\frac{1}{31}\)(30 phân số)

         =30/31

  B=1-\(\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}-\frac{1}{3}+...+\frac{1}{59}-\frac{1}{60}\)\(=\left(1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{59}\right)-\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{60}\right)\)

Bé nhất của của B là :\(\left(1+1+...+1\right)-\left(\frac{1}{60}+\frac{1}{60}+...+\frac{1}{60}\right)\)

                                \(=30-\frac{30}{60}\)

=>B>A

$A=\frac{{2005}^{2005}+1}{{2005}^{2006}+1}<\frac{{2005}^{2005}+1+2004}{{2005}^{2006}+1+2004}=\frac{2005.({2005}^{2004}+1)}{2005.({2005}^{2005}+1)}==\frac{{2005}^{2004}+1}{{2005}^{2005}+1}=B.$

Vậy A < B

$A=\frac{{2005}^{2005}+1}{{2005}^{2006}+1}<\frac{{2005}^{2005}+1+2004}{{2005}^{2006}+1+2004}=\frac{2005.({2005}^{2004}+1)}{2005.({2005}^{2005}+1)}==\frac{{2005}^{2004}+1}{{2005}^{2005}+1}=B.$

Vậy A < B

$A=\frac{{2005}^{2005}+1}{{2005}^{2006}+1}<\frac{{2005}^{2005}+1+2004}{{2005}^{2006}+1+2004}=\frac{2005.({2005}^{2004}+1)}{2005.({2005}^{2005}+1)}==\frac{{2005}^{2004}+1}{{2005}^{2005}+1}=B.$

Vậy A < B

CHÚC HỌC TỐT VÀ ĐỪNG QUÊN TICK NHA

\(B=\frac{1}{1.2}+\frac{1}{3.4}+...+\frac{1}{59.60}\)

\(B=1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{59}-\frac{1}{60}\)

\(B=\left(1+\frac{1}{3}+...+\frac{1}{59}\right)-\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{60}\right)\)

\(B=\left(1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+..+\frac{1}{59}+\frac{1}{60}\right)-2.\left(\frac{1}{2}+\frac{1}{4}+...+\frac{1}{50}\right)\)

\(B=\left(1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{49}+\frac{1}{50}\right)-\left(1+\frac{1}{2}+...+\frac{1}{30}\right)\)

\(B=\frac{1}{31}+\frac{1}{32}+\frac{1}{33}+...+\frac{1}{60}=A\)

A > B nhé tích mk vs

cậu giải giúp tớ cái 

???

Are you sure?

nói chung là :

làm đc vế a là làm đc vế b

$A=\frac{1}{2}+\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}$ 

$=\frac{16}{32}+\frac{8}{32}+\frac{4}{32}+\frac{2}{32}+\frac{1}{32}$ 

$=\frac{31}{32}$ 

Xét: $1-A=1-\frac{31}{32}=\frac{1}{32}$ 

Xét: $1-\frac{2023}{2024}=\frac{1}{2024}$ 

Vì: $32<2024$ 

$\Rightarrow \frac{1}{32}>\frac{1}{2024}$ 

$\Rightarrow 1-\frac{1}{32}<1-\frac{1}{2024}$ 

$\Rightarrow \frac{31}{32}<\frac{2023}{2024}$ 

$Vậy:A<\frac{2023}{2024}$ 

ko giải đâu

đùa thôi =)