125696

256x236+256x256-256=256x(236+256-1)=256x491=125696

125696

 tick đi 

mình tự làm đó

\(256\cdot236+256\cdot256-256=125696\)

\(A=256-\dfrac{256}{2}-\dfrac{256}{2^2}-\dfrac{256}{2^3}-.......-\dfrac{256}{2^9}\)
\(\Leftrightarrow A=256\left(1-\dfrac{1}{2}-\dfrac{1}{2^2}-\dfrac{1}{2^3}-.....-\dfrac{1}{2^9}\right)\)
Đặt \(B=\dfrac{1}{2}-\dfrac{1}{2^2}-\dfrac{1}{2^3}-.....-\dfrac{1}{2^9}\)
\(\Leftrightarrow2B=1-\dfrac{1}{2}-\dfrac{1}{2^2}-.....-\dfrac{1}{2^8}\)
\(\Leftrightarrow2B-B=1-\dfrac{1}{2^9}\)
\(\Leftrightarrow B=1-\dfrac{1}{2^9}\)
\(\Leftrightarrow A=256\left(1-\dfrac{1}{2^9}\right)\)
\(\Leftrightarrow A=256-\dfrac{1}{2^9}\)
\(\Leftrightarrow A=2^8-\dfrac{1}{2^9}\)
\(\Leftrightarrow A=\dfrac{2^{17}}{2^9}-\dfrac{1}{2^9}\)
\(\Leftrightarrow A=\dfrac{2^{17}-1}{2^9}\)
Vậy \(\Leftrightarrow A=\dfrac{2^{17}-1}{2^9}\)
Chúc bạn học tốt >w<

\(=\dfrac{64^2+256^2}{256^2+1024^2}=\dfrac{64^2\left(1+4^2\right)}{256^2\left(1+4^2\right)}=\left(\dfrac{64}{256}\right)^2=\dfrac{1}{16}\)

=3153,tk cho mình nha!

= 3153 nhe

= 3153  nhoa

các bạn ơi giúp mình với , mình cần gấp lắm

Mình chỉ biết là ra 1/16 thôi

-582

=954

= - 582

2x - ( -7) = 256-1146

2x -(-7) = -890

2x =-897 

x = -897 : 2 = -448.5

=> 2x + 7 = 256 - 256 - 89

=> 2x + 7 = -89

=> 2x = -96

=> x = -48