Question

Tìm số dư cho phép chia  2²⁰⁰⁶ :7

Answer 1

\(2^3\equiv1\left(mod7\right)\)

\(\Rightarrow\left(2^3\right)^{668}.2^2\equiv1^{668}.2^2\left(mod7\right)\)

\(\Rightarrow2^{2006}\equiv4\left(mod7\right)\)

-Vậy: \(2^{2006}\) chia 7 dư 4

Answer 2

\(2^{2006}=\left(2^{17}\right)^{118}=131072^{118}\)

Ma \(131072\equiv4\left(mod7\right)\)=>\(131072^{118}=4\left(mod7\right)\)

=> 131072^118 hay 2^2006 chia 7 du 3 

Answer 3

du 4 nha ban , ko phai 3 , minh an nham