Hs lớp 6A4 à?

\(A=\frac{2005^{2005}+1}{2^{2006}+1};B=\frac{2005^{2004}+1}{2^{2005}+1}\)

\(\frac{A}{B}=\frac{2005^{2005}+1}{2^{2006}+1}:\frac{2005^{2004}+1}{2^{2005}+1}\)

\(\frac{A}{B}=\frac{2005^{2005}+1}{2^{2006}+1}\cdot\frac{2^{2005}+1}{2005^{2004}+1}\)

\(\frac{A}{B}=\frac{2005^{2005}+1}{2005^{2004}+1}\cdot\frac{2^{2005}+1}{2^{2006}+1}\)

\(\frac{A}{B}=\frac{2005\cdot2005^{2004}+1}{2005^{2004}+1}\cdot\frac{2^{2005}+1}{2\cdot2^{2005}+1}\)

\(\frac{A}{B}\thickapprox x\cdot\frac12\thickapprox2005\cdot\frac12=1002,5\)

\(\Rightarrow A>B\)

Vậy A > B

?????????????

[sửa]: \(2\cdot3^{x+1}=10\cdot3^{12}-8\cdot3^{12}\)

\(2\cdot3^{x+1}=\left(10-8\right)\cdot3^{12}\)

\(2\cdot3^{x+1}=2\cdot3^{12}\)

\(\to3^{x+1}=3^{12}\)

\(\Rightarrow x+1=12\)

\(x=12-1\)

\(x=11\)

Vậy x = 11

tìm hiểu về bài học nào v bn?

 William James Sidis chỉ số IQ 250 - 300

William James Sidis ( IQ: 250-300)

William James Sidis ( IQ: 250-300)

hay nha!!

Ta thấy: \(5^{b}=\overline{\ldots5}\) là số lẻ

Mà 124 là số chẵn

⇒ \(2^{a}\) phải là số lẻ

\(\to2^{a}=2^0=1\)

⇒ a = 0

\(\Rightarrow5^{b}=1+124=125=5^3\)

⇒ b = 3

Vậy (a, b) = (0; 3)