\(A=1+5+5^2+5^3+..+5^{100}\)

\(5A=5+5^2+5^3+..+5^{101}\)

\(A=\frac{5^{101}-1}{4}\)\(SUYRA\) \(A< B\)

\(A=5^0+5+5^2+...+5^{100}.\)

\(\Rightarrow5A=5+5^2+5^3+...+5^{101}\)

\(\Rightarrow5A-A=4A=\left(5+5^2+5^3+...+5^{101}\right)-\left(5^0+5+5^2+...+5^{100}\right)\)

                                \(=5^{101}-1\)

\(\Rightarrow A=\frac{5^{101}-1}{4}\)

Còn lại tự lm nha bn

\(\dfrac{11}{-13}=-\dfrac{11}{13}=-\dfrac{13}{13}+\dfrac{2}{13}=-1+\dfrac{2}{13}\\ -\dfrac{14}{15}=-\dfrac{15}{15}+\dfrac{1}{15}=-1+\dfrac{1}{15}\)

Ta thấy : \(\dfrac{1}{15}< \dfrac{1}{13}< \dfrac{2}{13}=>-1+\dfrac{1}{15}< -1+\dfrac{2}{13}\)

hay \(\dfrac{11}{-13}>-\dfrac{14}{15}\)

A=1/2+1/22+1/23+...+1/22020+1/22021 > B=1/3+1/4+1/5+13/60

Ta có: $A=\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+\frac{1}{2^4}+...+\frac{1}{2^{2021}}+\frac{1}{2^{2022}}$

$\Rightarrow 2A=1+\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^{2020}}+\frac{1}{2^{2021}}$

$\Rightarrow 2A-A=(1+\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^{2020}}+\frac{1}{2^{}}$

a) \(\frac{{ - 21}}{{10}}\) < 0

b) \(\frac{{ - 5}}{{ - 2}} = \frac{5}{2} > 0\). Vậy \(\frac{{ - 5}}{{ - 2}} > 0\).

c) \(\frac{{ - 5}}{{ - 2}} = \frac{5}{2} > 0\), mà \(\frac{{ - 21}}{{10}} < 0\)

Vậy \(\frac{{ - 5}}{{ - 2}} > \frac{{ - 21}}{{10}}\).

a: \(-\dfrac{21}{10}< 0\)

b: \(0< -\dfrac{5}{-2}\)

c: \(-\dfrac{21}{10}< 0< \dfrac{-5}{-2}\)

a) Vì \(\dfrac{1}{24}< \dfrac{1}{83}\) 

⇒ \(\dfrac{1}{24^9}>\dfrac{1}{83^{13}}\)

a) \(\left(\dfrac{1}{24}\right)^9>\left(\dfrac{1}{27}\right)^9=\dfrac{1}{3^{27}}\)

\(\left(\dfrac{1}{83}\right)^{13}< \left(\dfrac{1}{81}\right)^{13}=\dfrac{1}{3^{52}}\)

Mà \(\dfrac{1}{3^{27}}>\dfrac{1}{3^{52}}\)

\(\Rightarrow\left(\dfrac{1}{24}\right)^9>\left(\dfrac{1}{83}\right)^{13}\)

b) \(3^{300}=\left(3^3\right)^{100}=27^{100}\)

\(5^{199}< 5^{200}=\left(5^2\right)^{100}=25^{100}\)

Mà \(25^{100}< 27^{100}\)

\(\Rightarrow5^{199}< 3^{300}\)

\(\Rightarrow\dfrac{1}{5^{199}}>\dfrac{1}{3^{300}}\)

\(a,\left(\dfrac{1}{24}\right)^9=\dfrac{1}{24^9};\left(\dfrac{1}{83}\right)^{13}=\dfrac{1}{83^{13}};24^9< 83^{13}\left(24< 83;9< 13\right)\\ \Rightarrow\dfrac{1}{24^9}< \dfrac{1}{83^{13}}\Rightarrow\left(\dfrac{1}{24}\right)^9< \left(\dfrac{1}{83}\right)^{13}\\ b,3^{300}=27^{100}>25^{100}=5^{200}>5^{199}\\ \Rightarrow\dfrac{1}{3^{300}}< \dfrac{1}{5^{199}}\)

a: Ta có: \(3^{2020}=3^{2018}\cdot3^2=3^{2018}\cdot9\)

mà 9<10

nên \(3^{2020}< 10\cdot3^{2018}\)

a) Ta có:

\(\dfrac{16}{9}\)=\(\dfrac{48}{27}\)                 \(\dfrac{24}{13}=\dfrac{48}{26}\)

Vì 27>26

➝\(\dfrac{48}{27}>\dfrac{48}{26}hay\dfrac{16}{9}>\dfrac{24}{13}\)

So sánh:

a) 16/9 và 24/13 

 Ta có \(\dfrac{16}{9}=\dfrac{208}{117}\) và \(\dfrac{24}{13}=\) \(\dfrac{216}{117}\)

\(\Rightarrow\dfrac{216}{117}>\dfrac{208}{117}\Rightarrow\dfrac{24}{13}>\dfrac{16}{9}\)

b) 27/82 và 26/75

Ta có \(\dfrac{27}{82}\approx0,33\) và \(\dfrac{26}{75}\approx0,35\)

\(\Rightarrow9,35>0,33\Rightarrow\dfrac{26}{75}>\dfrac{27}{82}\)

a) Ta có: \(\dfrac{16}{9}=\dfrac{16\cdot13}{9\cdot13}=\dfrac{208}{117}\)

\(\dfrac{24}{13}=\dfrac{24\cdot9}{13\cdot9}=\dfrac{216}{117}\)

mà \(\dfrac{208}{117}< \dfrac{216}{117}\)

nên \(\dfrac{16}{9}< \dfrac{24}{13}\)

\(A=1+2+2^2+...+2^{2022}\)

\(\Rightarrow2A=2+2^2+...+2^{2023}\)

\(\Rightarrow2A-A=2^{2023}-1\)

\(\Rightarrow A=2^{2023}-1\)

\(\Rightarrow A< 2^{2023}=2^2.2^{2021}=4.2^{2021}< 5^{2021}\)

\(\Rightarrow A< B\)

a)

\(\begin{array}{l}{( - 3)^2}.{( - 3)^4} = 9.81 = 729\\ {( - 3)^6} = ( - 3).( - 3).( - 3).( - 3).( - 3).( - 3)\\ = 9.9.9 = 729\end{array}\)

Vậy \({( - 3)^2}.{( - 3)^4}\) = \({( - 3)^{6}}\)

b)

\(\begin{array}{l}0,6{}^3:0,{6^2} = 0,216:0,36 = 0,6\end{array}\)

Vậy \(0,6{}^3:0,{6^2}\) = \(0,{6}\)