\(\frac{33}{2}+\frac{33}{6}+\frac{33}{18}+\frac{33}{54}+\frac{33}{162}+\frac{33}{486}\)

\(=\frac{33.3+33.3+33.3+33.3+33.3}{486}\)

\(=\frac{99.5}{486}\)

\(=\frac{495}{486}\)

Gọi \(A=\frac{33}{2}+\frac{33}{6}+...+\frac{33}{486}\)

\(A=33.\left[\left(\frac{1}{1.2}+\frac{1}{2.3}\right)+\left(\frac{1}{3.6}+\frac{1}{6.9}\right)\left(\frac{1}{9.18}+\frac{1}{18.27}\right)\right]\)

\(A=33.\left[\frac{2}{3}+\frac{2}{9}+\frac{2}{27}\right]\)

\(A=66.\left[\frac{9}{27}+\frac{3}{27}+\frac{1}{27}\right]\)

\(A=66.\frac{13}{27}\)

\(A=\frac{286}{9}\)

sai hay đúng cx ko biết nha

wow! mù mắt. Ido tính toán có khác!

C2:(32+1)x32:2=528

bạn tính thử xem đúng đấy.

Ta có:

2m−2n=5122m−2n=512

⇒2n.(2m−n−1)=512⇒2n.(2m−n−1)=512

2m−2n=5122m−2n=512

⇒2m>2n.⇒2m>2n.

⇒m>n⇒m>n

⇒2m−n−1⇒2m−n−1 là số lẻ.

⇒2m−n−1=1⇒2m−n−1=1

⇒2n.1=512⇒2n.1=512

⇒2n=512:1⇒2n=512:1

⇒2n=512⇒2n=512

⇒2n=29⇒2n=29

⇒n=9.⇒n=9.

⇒2m=512+512⇒2m=512+512

⇒2m=1024⇒2m=1024

⇒2m=210⇒2m=210

⇒m=10.⇒m=10.

Vậy m=10;n=9.

=> 2ⁿ(2^m-n - 1)=512

2^m - 2ⁿ = 512

=> 2^m > 2ⁿ 

=> m>n

Ta có 2^m-n là 1 số luôn chẵn

=> 2^m-n - 1  là 1 số luôn lẻ

Ta đặt 2^m-n-1 =1

=>  2ⁿ(2^m-n - 1)= 2ⁿ . 1 = 2ⁿ = 512 = 2⁹ 

=> n=9

Ta thay n=9

=> 2^m - 2ⁿ = 512

      2^m - 512= 512

      2^m         = 512+512 =1024 = 2¹⁰ 

=> m=10

Kết luận : m=10 ; n= 9

Học tốt nhé!

\(=2.\left[\left(7-1\right):22+99\right]-100\\ =2.\left(6:22+99\right)-100\\ =2.\left(\dfrac{3}{11}+99\right)-100\\ =2.\left(\dfrac{3}{11}+\dfrac{1089}{11}\right)-100\\ =2.\dfrac{1092}{11}-100\\ =\dfrac{2184}{11}-100\\ =\dfrac{1084}{11}\)

\(2.\left[\left(7-33:33\right):22+99\right]-100\)

\(=2.\left[\left(7-1\right):22+99\right]-100\)

\(=2.\left(6:22+99\right)-100\)

\(=2.\left(\dfrac{3}{11}+99\right)-100\)

\(=2.\dfrac{1092}{11}-100\)

\(=\dfrac{2184}{11}-100\)

\(=\dfrac{1084}{11}\)

\(\left(\frac{2}{31\times33}+\frac{2}{33\times35}+...+\frac{2}{39\times41}\right)\times2542-2,04:x=19\)

\(\Rightarrow\left(\frac{1}{31}-\frac{1}{33}+\frac{1}{33}-\frac{1}{35}+...+\frac{1}{39}-\frac{1}{41}\right)\times2542-2,04:x=19\)

\(\Rightarrow\left(\frac{1}{31}-\frac{1}{41}\right)\times2542-2,04:x=19\)

\(\Rightarrow\frac{10}{1271}\times2542-2,04:x=19\)

\(\Rightarrow20-2,04:x=19\)

\(\Rightarrow2,04:x=20-19\)

\(\Rightarrow2,04:x=1\)

\(\Rightarrow x=2,04:1\)

\(\Rightarrow x=2,04\)

Vậy x = 2,04

\(\left(\frac{2}{31\text{ x }33}+\frac{2}{33\text{ x }35}+...+\frac{2}{39\text{ x }41}\right)\text{ x }2542-2,04\text{ : }x=19\)

\(\left(\frac{1}{31}-\frac{1}{33}+\frac{1}{33}-\frac{1}{35}+...+\frac{1}{39}-\frac{1}{41}\right)\text{ x }2542-2,04\text{ : }x=1\)

\(\left(\frac{1}{31}-\frac{1}{41}\right)\text{ x }2542-2,04\text{ : }x=1\)

\(\frac{10}{1271}\text{ x }2542-2,04\text{ : }x=1\)

\(20-2,04\text{ : }x=1\)

\(2,04\text{ : }x=20-1\)

\(2,04\text{ : }x=19\)

\(x=2,04\text{ : }19\)

\(x=\frac{51}{475}\)

\(\dfrac{15}{17}\)

\(=\dfrac{15}{17}\left(\dfrac{45}{33}-\dfrac{12}{33}\right)=\dfrac{15}{17}\)